fyrox_ui/

window.rs

// Copyright (c) 2019-present Dmitry Stepanov and Fyrox Engine contributors.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

//! The Window widget provides a standard window that can contain another widget. See [`Window`] docs
//! for more info and usage examples.

use crate::button::Button;
use crate::grid::Grid;
use crate::message::MessageData;
use crate::vector_image::VectorImage;
use crate::{
    border::BorderBuilder,
    brush::Brush,
    button::{ButtonBuilder, ButtonMessage},
    core::{
        algebra::Vector2, color::Color, log::Log, math::Rect, pool::Handle, reflect::prelude::*,
        type_traits::prelude::*, uuid_provider, visitor::prelude::*,
    },
    decorator::DecoratorBuilder,
    font::FontResource,
    grid::{Column, GridBuilder, Row},
    message::{CursorIcon, KeyCode, UiMessage},
    navigation::NavigationLayerBuilder,
    style::{resource::StyleResourceExt, Style, StyledProperty},
    text::{Text, TextBuilder, TextMessage},
    vector_image::{Primitive, VectorImageBuilder},
    widget::{Widget, WidgetBuilder, WidgetMessage},
    BuildContext, Control, HorizontalAlignment, RestrictionEntry, Thickness, UiNode, UserInterface,
    VerticalAlignment,
};
use fyrox_core::pool::ObjectOrVariant;
use fyrox_graph::{
    constructor::{ConstructorProvider, GraphNodeConstructor},
    SceneGraph,
};
use std::cell::RefCell;

#[derive(Debug, Clone, Copy, PartialEq)]
pub enum WindowAlignment {
    /// No specific alignment.
    None,
    /// Center of the parent widget (in most cases - center of the screen, if the parent is not
    /// specified).
    Center,
    /// Position (in local coordinates) relative to the left top corner of the parent widget
    /// bounds. In most cases, it is just screen coordinates.
    Position(Vector2<f32>),
    /// Relative alignment to the specified widget.
    Relative {
        /// A handle of a node to which the sender of this message should be aligned to.
        relative_to: Handle<UiNode>,
        /// Horizontal alignment of the widget.
        horizontal_alignment: HorizontalAlignment,
        /// Vertical alignment of the widget.
        vertical_alignment: VerticalAlignment,
        /// Margins for each side.
        margin: Thickness,
    },
}

/// A set of possible messages that can be used to modify the state of a window or listen to changes
/// in the window.
#[derive(Debug, Clone, PartialEq)]
pub enum WindowMessage {
    /// Opens a window.
    Open {
        /// A flag that defines whether the window should be centered or not.
        alignment: WindowAlignment,
        /// Should the window be opened in modal mode or not.
        modal: bool,
        /// A flag that defines whether the content of the window should be focused when the window
        /// is opening.
        focus_content: bool,
    },

    /// Closes a window.
    Close,

    /// Minimizes a window - it differs from classic minimization in window managers,
    /// instead of putting window in system tray, it just collapses internal content panel.
    Minimize(bool),

    /// Forces the window to take the inner size of the main application window.
    Maximize(bool),

    /// Whether window can be minimized by _ mark. false hides _ mark.
    CanMinimize(bool),

    /// Whether window can be closed by X mark. false hides X mark.
    CanClose(bool),

    /// Whether window can be resized by resize grips.
    CanResize(bool),

    /// Indicates that move has been started. You should never send this message by hand.
    MoveStart,

    /// Moves window to a new position in local coordinates.
    Move(Vector2<f32>),

    /// Indicated that move has ended. You should never send this message by hand.
    MoveEnd,

    /// Sets new window title.
    Title(WindowTitle),

    /// Safe border size defines "part" of a window that should always be on screen when dragged.
    /// It is used to prevent moving window outside of main application window bounds, to still
    /// be able to drag it.
    SafeBorderSize(Option<Vector2<f32>>),
}
impl MessageData for WindowMessage {}

/// The state of a window's size, as controlled by the buttons in the top-right corner.
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, Visit, Reflect)]
pub enum WindowSizeState {
    /// The window is neither maximized nor minimized, showing its content and free to move around the screen.
    #[default]
    Normal,
    /// The window is hiding its content.
    Minimized,
    /// The window is filling the screen.
    Maximized,
}

/// The Window widget provides a standard window that can contain another widget. Based on setting,
/// windows can be configured so users can do any of the following:
///
/// * Movable by the user. Not configurable.
/// * Have title text on the title bar. Set by the *with_title* function.
/// * Able to be exited by the user. Set by the *can_close* function.
/// * Able to be minimized to just the Title bar, and of course maximized again. Set by the
/// *can_minimize* function.
/// * Able to resize the window. Set by the *can_resize* function.
///
/// As with other UI elements, you create and configure the window using the WindowBuilder.
///
/// ```rust,no_run
/// # use fyrox_ui::{
/// #     core::{pool::Handle, algebra::Vector2},
/// #     window::{WindowBuilder, WindowTitle},
/// #     text::TextBuilder,
/// #     widget::WidgetBuilder,
/// #     UiNode,
/// #     UserInterface
/// # };
/// fn create_window(ui: &mut UserInterface) {
///     WindowBuilder::new(
///         WidgetBuilder::new()
///             .with_desired_position(Vector2::new(300.0, 0.0))
///             .with_width(300.0),
///     )
///     .with_content(
///         TextBuilder::new(WidgetBuilder::new())
///             .with_text("Example Window content.")
///             .build(&mut ui.build_ctx())
///     )
///     .with_title(WindowTitle::text("Window"))
///     .can_close(true)
///     .can_minimize(true)
///     .open(true)
///     .can_resize(false)
///     .build(&mut ui.build_ctx());
/// }
/// ```
///
/// You will likely want to constrain the initial size of the window to something as shown in the
/// example by providing a set width and/or height to the base WidgetBuilder. Otherwise, it will
/// expand to fit its content.
///
/// You may also want to set an initial position with the *with_desired_position* function called
/// on the base WidgetBuilder which sets the position of the window's top-left corner. Otherwise, all
/// your windows will start with its top-left corner at 0,0 and be stacked on top of each other.
///
/// Windows can only contain a single direct child widget, set by using the *with_content* function.
/// Additional calls to *with_content* replace the widgets given in previous calls, and the old
/// widgets exist outside the window, so you should delete old widgets before changing a window's
/// widget. If you want multiple widgets, you need to use one of the layout container widgets like
/// the Grid, Stack Panel, etc. then add the additional widgets to that widget as needed.
///
/// The Window is a user editable object, but can only be affected by UI Messages they trigger if
/// the message's corresponding variable has been set to true aka what is set by the *can_close*,
/// *can_minimize*, and *can_resize* functions.
///
/// ## Initial Open State
///
/// By default, the window will be created in the open, or maximized, state. You can manually set
/// this state via the *open* function providing a true or false as desired.
///
/// ## Styling the Buttons
///
/// The window close and minimize buttons can be configured with the *with_close_button* and
/// *with_minimize_button* functions. You will want to pass them a button widget, but can do anything
/// else you like past that.
///
/// ## Modal (AKA Forced Focus)
///
/// A Modal in UI design terms indicates a window or box that has forced focus. The user is not able
/// to interact with anything else until the modal is dismissed.
///
/// Any window can be set and unset as a modal via the *modal* function.
#[derive(Default, Clone, Visit, Reflect, Debug, ComponentProvider)]
#[reflect(derived_type = "UiNode")]
pub struct Window {
    /// Base widget of the window.
    pub widget: Widget,
    /// The text to put in the tab for this window.
    tab_label: String,
    /// Mouse click position.
    pub mouse_click_pos: Vector2<f32>,
    /// Initial mouse position.
    pub initial_position: Vector2<f32>,
    /// Initial size of the window.
    pub initial_size: Vector2<f32>,
    /// Whether the window is being dragged or not.
    pub is_dragging: bool,
    /// Whether the window is minimized, maximized, or normal.
    pub size_state: WindowSizeState,
    /// Whether the window can be minimized or not.
    pub can_minimize: bool,
    /// Whether the window can be maximized or not.
    pub can_maximize: bool,
    /// Whether the window can be closed or not.
    pub can_close: bool,
    /// Whether the window can be resized or not.
    pub can_resize: bool,
    /// Handle of a header widget.
    pub header: Handle<UiNode>,
    /// Handle of a minimize button.
    pub minimize_button: Handle<Button>,
    /// Handle of a maximize button.
    pub maximize_button: Handle<Button>,
    /// Handle of a close button.
    pub close_button: Handle<Button>,
    /// A distance per each axis when the dragging starts.
    pub drag_delta: Vector2<f32>,
    /// Handle of a current content.
    pub content: Handle<UiNode>,
    /// Eight grips of the window that are used to resize the window.
    pub grips: RefCell<[Grip; 8]>,
    /// Handle of a title widget of the window.
    pub title: Handle<UiNode>,
    /// Handle of a container widget of the title.
    pub title_grid: Handle<Grid>,
    /// Optional size of the border around the screen in which the window will be forced to stay.
    pub safe_border_size: Option<Vector2<f32>>,
    /// Bounds of the window before maximization, it is used to return the window to previous
    /// size when it is either "unmaximized" or dragged.
    pub prev_bounds: Option<Rect<f32>>,
    /// If `true`, then the window can be closed using `Esc` key. Default is `true`. Works only if
    /// `can_close` is also `true`.
    pub close_by_esc: bool,
    /// If `true`, then the window will be deleted after closing.
    pub remove_on_close: bool,
}

impl ConstructorProvider<UiNode, UserInterface> for Window {
    fn constructor() -> GraphNodeConstructor<UiNode, UserInterface> {
        GraphNodeConstructor::new::<Self>()
            .with_variant("Window", |ui| {
                WindowBuilder::new(WidgetBuilder::new().with_name("Window"))
                    .build(&mut ui.build_ctx())
                    .to_base()
                    .into()
            })
            .with_group("Layout")
    }
}

const GRIP_SIZE: f32 = 6.0;
const CORNER_GRIP_SIZE: f32 = GRIP_SIZE * 2.0;

/// Kind of a resizing grip.
#[derive(Copy, Clone, Debug, Visit, Reflect, Default)]
pub enum GripKind {
    /// Left-top corner grip.
    #[default]
    LeftTopCorner = 0,
    /// Right-top corner grip.
    RightTopCorner = 1,
    /// Right-bottom corner grip.
    RightBottomCorner = 2,
    /// Left-bottom corner grip.
    LeftBottomCorner = 3,
    /// Left corner grip.
    Left = 4,
    /// Top corner grip.
    Top = 5,
    /// Right corner grip.
    Right = 6,
    /// Bottom corner grip.
    Bottom = 7,
}

/// Resizing grip.
#[derive(Clone, Visit, Default, Debug, Reflect)]
pub struct Grip {
    /// Kind of the grip.
    pub kind: GripKind,
    /// Bounds of the grip in local-space.
    pub bounds: Rect<f32>,
    /// A flag, that is raised when the grip is being dragged.
    pub is_dragging: bool,
    /// Cursor type of the grip.
    pub cursor: CursorIcon,
}

impl Grip {
    fn new(kind: GripKind, cursor: CursorIcon) -> Self {
        Self {
            kind,
            bounds: Default::default(),
            is_dragging: false,
            cursor,
        }
    }
}

crate::define_widget_deref!(Window);

uuid_provider!(Window = "9331bf32-8614-4005-874c-5239e56bb15e");

impl Control for Window {
    fn arrange_override(&self, ui: &UserInterface, final_size: Vector2<f32>) -> Vector2<f32> {
        let size = self.widget.arrange_override(ui, final_size);

        let mut grips = self.grips.borrow_mut();

        // Adjust grips.
        grips[GripKind::Left as usize].bounds =
            Rect::new(0.0, GRIP_SIZE, GRIP_SIZE, final_size.y - GRIP_SIZE * 2.0);
        grips[GripKind::Top as usize].bounds =
            Rect::new(GRIP_SIZE, 0.0, final_size.x - GRIP_SIZE * 2.0, GRIP_SIZE);
        grips[GripKind::Right as usize].bounds = Rect::new(
            final_size.x - GRIP_SIZE,
            GRIP_SIZE,
            GRIP_SIZE,
            final_size.y - GRIP_SIZE * 2.0,
        );
        grips[GripKind::Bottom as usize].bounds = Rect::new(
            GRIP_SIZE,
            final_size.y - GRIP_SIZE,
            final_size.x - GRIP_SIZE * 2.0,
            GRIP_SIZE,
        );

        // Corners have different size to improve usability.
        grips[GripKind::LeftTopCorner as usize].bounds =
            Rect::new(0.0, 0.0, CORNER_GRIP_SIZE, CORNER_GRIP_SIZE);
        grips[GripKind::RightTopCorner as usize].bounds = Rect::new(
            final_size.x - GRIP_SIZE,
            0.0,
            CORNER_GRIP_SIZE,
            CORNER_GRIP_SIZE,
        );
        grips[GripKind::RightBottomCorner as usize].bounds = Rect::new(
            final_size.x - CORNER_GRIP_SIZE,
            final_size.y - CORNER_GRIP_SIZE,
            CORNER_GRIP_SIZE,
            CORNER_GRIP_SIZE,
        );
        grips[GripKind::LeftBottomCorner as usize].bounds = Rect::new(
            0.0,
            final_size.y - CORNER_GRIP_SIZE,
            CORNER_GRIP_SIZE,
            CORNER_GRIP_SIZE,
        );

        size
    }

    fn handle_routed_message(&mut self, ui: &mut UserInterface, message: &mut UiMessage) {
        self.widget.handle_routed_message(ui, message);

        if let Some(msg) = message.data::<WidgetMessage>() {
            // Grip interaction have higher priority than other actions.
            if self.can_resize && !self.is_dragging {
                match msg {
                    &WidgetMessage::MouseDown { pos, .. } => {
                        ui.send(self.handle(), WidgetMessage::Topmost);

                        if !self.maximized() {
                            // Check grips.
                            for grip in self.grips.borrow_mut().iter_mut() {
                                let screen_bounds = grip.bounds.transform(&self.visual_transform);
                                if screen_bounds.contains(pos) {
                                    grip.is_dragging = true;
                                    self.initial_position = self.screen_position();
                                    self.initial_size = self.actual_local_size();
                                    self.mouse_click_pos = pos;
                                    ui.capture_mouse(self.handle());
                                    break;
                                }
                            }
                        }
                    }
                    WidgetMessage::MouseUp { .. } => {
                        for grip in self.grips.borrow_mut().iter_mut() {
                            if grip.is_dragging {
                                ui.release_mouse_capture();
                                grip.is_dragging = false;
                                break;
                            }
                        }
                    }
                    &WidgetMessage::MouseMove { pos, .. } => {
                        let mut new_cursor = None;

                        if !self.maximized() {
                            for grip in self.grips.borrow().iter() {
                                let screen_bounds = grip.bounds.transform(&self.visual_transform);
                                if grip.is_dragging || screen_bounds.contains(pos) {
                                    new_cursor = Some(grip.cursor);
                                }

                                if grip.is_dragging {
                                    let parent = ui.node(self.parent());
                                    let click_pos = parent.screen_to_local(self.mouse_click_pos);
                                    let current_pos = parent.screen_to_local(pos);
                                    let delta = click_pos - current_pos;
                                    let (dx, dy, dw, dh) = match grip.kind {
                                        GripKind::Left => (-1.0, 0.0, 1.0, 0.0),
                                        GripKind::Top => (0.0, -1.0, 0.0, 1.0),
                                        GripKind::Right => (0.0, 0.0, -1.0, 0.0),
                                        GripKind::Bottom => (0.0, 0.0, 0.0, -1.0),
                                        GripKind::LeftTopCorner => (-1.0, -1.0, 1.0, 1.0),
                                        GripKind::RightTopCorner => (0.0, -1.0, -1.0, 1.0),
                                        GripKind::RightBottomCorner => (0.0, 0.0, -1.0, -1.0),
                                        GripKind::LeftBottomCorner => (-1.0, 0.0, 1.0, -1.0),
                                    };

                                    let initial_position =
                                        parent.screen_to_local(self.initial_position);
                                    let new_pos = if self.minimized() {
                                        initial_position + Vector2::new(delta.x * dx, 0.0)
                                    } else {
                                        initial_position + Vector2::new(delta.x * dx, delta.y * dy)
                                    };
                                    let new_size = self.initial_size
                                        + Vector2::new(delta.x * dw, delta.y * dh);
                                    let mut clamped_size = self.initial_size;
                                    let mut clamped_pos = new_pos;

                                    if dw != 0.0 {
                                        clamped_size.x =
                                            new_size.x.clamp(self.min_width(), self.max_width());
                                        if dx != 0.0 {
                                            let right_edge =
                                                initial_position.x + self.initial_size.x;
                                            clamped_pos.x = right_edge - clamped_size.x;
                                        }
                                    }

                                    if dh != 0.0 {
                                        clamped_size.y =
                                            new_size.y.clamp(self.min_height(), self.max_height());
                                        if dy != 0.0 {
                                            let bottom_edge =
                                                initial_position.y + self.initial_size.y;
                                            clamped_pos.y = bottom_edge - clamped_size.y;
                                        }
                                    }

                                    ui.send_many(
                                        self.handle(),
                                        [
                                            WidgetMessage::DesiredPosition(clamped_pos),
                                            WidgetMessage::Width(clamped_size.x),
                                        ],
                                    );
                                    if !self.minimized() {
                                        ui.send(
                                            self.handle(),
                                            WidgetMessage::Height(clamped_size.y),
                                        );
                                    }

                                    break;
                                }
                            }
                        }

                        self.set_cursor(new_cursor);
                    }
                    _ => {}
                }
            } else {
                // The window cannot be resized, so leave the cursor unset.
                self.set_cursor(None);
            }

            if (message.destination() == self.header
                || ui
                    .node(self.header)
                    .has_descendant(message.destination(), ui))
                && !self.maximized()
                && !message.handled()
                && !self.has_active_grip()
            {
                match msg {
                    WidgetMessage::MouseDown { pos, .. } => {
                        self.mouse_click_pos = *pos;
                        ui.send(self.handle, WindowMessage::MoveStart);
                        message.set_handled(true);
                    }
                    WidgetMessage::MouseUp { .. } => {
                        ui.send(self.handle, WindowMessage::MoveEnd);
                        message.set_handled(true);
                    }
                    WidgetMessage::MouseMove { pos, .. } => {
                        if self.is_dragging {
                            self.drag_delta = *pos - self.mouse_click_pos;
                            let new_pos = self.initial_position + self.drag_delta;
                            ui.send(
                                self.handle(),
                                WindowMessage::Move(ui.screen_to_root_canvas_space(new_pos)),
                            );
                        }
                        message.set_handled(true);
                    }
                    _ => (),
                }
            }
            match msg {
                WidgetMessage::Unlink => {
                    if message.destination() == self.handle() {
                        self.initial_position = self.screen_position();
                    }
                }
                WidgetMessage::KeyDown(key_code)
                    if self.close_by_esc
                        && !self.is_docked(ui)
                        && self.can_close
                        && *key_code == KeyCode::Escape
                        && !message.handled() =>
                {
                    ui.send(self.handle, WindowMessage::Close);
                    message.set_handled(true);
                }
                _ => {}
            }
        } else if let Some(ButtonMessage::Click) = message.data::<ButtonMessage>() {
            if message.destination() == self.minimize_button {
                ui.send(self.handle(), WindowMessage::Minimize(!self.minimized()));
            } else if message.destination() == self.maximize_button {
                ui.send(self.handle(), WindowMessage::Maximize(!self.maximized()));
            } else if message.destination() == self.close_button {
                ui.send(self.handle(), WindowMessage::Close);
            }
        } else if let Some(msg) = message.data_for::<WindowMessage>(self.handle()) {
            match msg {
                &WindowMessage::Open {
                    alignment,
                    modal,
                    focus_content,
                } => {
                    // Only manage this window's visibility if it is at the root.
                    // Otherwise, it is part of something like a tile, and that parent should decide
                    // whether the window is visible.
                    if !self.visibility() && self.parent() == ui.root() {
                        ui.send(self.handle(), WidgetMessage::Visibility(true));
                        // If we are opening the window with non-finite width and height, something
                        // has gone wrong, so correct it.
                        if !self.width().is_finite() {
                            Log::err(format!("Window width was {}", self.width()));
                            self.set_width(200.0);
                        }
                        if !self.height().is_finite() {
                            Log::err(format!("Window height was {}", self.height()));
                            self.set_height(200.0);
                        }
                    }
                    ui.send(self.handle(), WidgetMessage::Topmost);
                    if focus_content {
                        ui.send(self.content_to_focus(), WidgetMessage::Focus);
                    }
                    if modal && !ui.restricts_picking(self.handle()) {
                        ui.push_picking_restriction(RestrictionEntry {
                            handle: self.handle(),
                            stop: true,
                        });
                    }
                    match alignment {
                        WindowAlignment::None => {}
                        WindowAlignment::Center => {
                            if self.parent() == ui.root() {
                                ui.send(self.handle(), WidgetMessage::Center);
                            }
                        }
                        WindowAlignment::Position(position) => {
                            ui.send(self.handle(), WidgetMessage::DesiredPosition(position));
                        }
                        WindowAlignment::Relative {
                            relative_to,
                            horizontal_alignment,
                            vertical_alignment,
                            margin,
                        } => {
                            ui.send(
                                self.handle(),
                                WidgetMessage::Align {
                                    relative_to,
                                    horizontal_alignment,
                                    vertical_alignment,
                                    margin,
                                },
                            );
                        }
                    }
                }
                WindowMessage::Close => {
                    if self.visibility() {
                        ui.send(self.handle(), WidgetMessage::Visibility(false));
                        ui.remove_picking_restriction(self.handle());
                        if self.remove_on_close {
                            ui.send(self.handle(), WidgetMessage::Remove);
                        }
                    }
                }
                &WindowMessage::Minimize(minimized) => {
                    if minimized {
                        self.update_size_state(WindowSizeState::Minimized, ui);
                    } else {
                        self.update_size_state(WindowSizeState::Normal, ui);
                    }
                }
                &WindowMessage::Maximize(maximized) => {
                    if maximized {
                        self.update_size_state(WindowSizeState::Maximized, ui);
                    } else {
                        self.update_size_state(WindowSizeState::Normal, ui);
                    }
                }
                &WindowMessage::CanMinimize(value) => {
                    if self.can_minimize != value {
                        self.can_minimize = value;
                        if self.minimize_button.is_some() {
                            ui.send(self.minimize_button, WidgetMessage::Visibility(value));
                        }
                    }
                }
                &WindowMessage::CanClose(value) => {
                    if self.can_close != value {
                        self.can_close = value;
                        if self.close_button.is_some() {
                            ui.send(self.close_button, WidgetMessage::Visibility(value));
                        }
                    }
                }
                &WindowMessage::CanResize(value) => {
                    if self.can_resize != value {
                        self.can_resize = value;
                        ui.try_send_response(message);
                    }
                }
                &WindowMessage::Move(mut new_pos) => {
                    if let Some(safe_border) = self.safe_border_size {
                        // Clamp new position in allowed bounds. This will prevent moving the window outside the main
                        // application window, thus leaving an opportunity to drag the window to some other place.
                        new_pos.x = new_pos.x.clamp(
                            -(self.actual_local_size().x - safe_border.x).abs(),
                            (ui.screen_size().x - safe_border.x).abs(),
                        );
                        new_pos.y = new_pos
                            .y
                            .clamp(0.0, (ui.screen_size().y - safe_border.y).abs());
                    }

                    if self.is_dragging && self.desired_local_position() != new_pos {
                        ui.send(self.handle(), WidgetMessage::DesiredPosition(new_pos));
                        ui.try_send_response(message);
                    }
                }
                WindowMessage::MoveStart => {
                    if !self.is_dragging {
                        ui.capture_mouse(self.header);
                        let initial_position = self.screen_position();
                        self.initial_position = initial_position;
                        self.is_dragging = true;

                        if self.size_state == WindowSizeState::Maximized {
                            self.size_state = WindowSizeState::Normal;
                            if let Some(prev_bounds) = self.prev_bounds.take() {
                                ui.send_many(
                                    self.handle,
                                    [
                                        WidgetMessage::Width(prev_bounds.w()),
                                        WidgetMessage::Height(prev_bounds.h()),
                                    ],
                                );
                            }
                        }

                        ui.try_send_response(message);
                    }
                }
                WindowMessage::MoveEnd => {
                    if self.is_dragging {
                        ui.release_mouse_capture();
                        self.is_dragging = false;

                        ui.try_send_response(message);
                    }
                }
                WindowMessage::Title(title) => {
                    match title {
                        WindowTitle::Text {
                            text,
                            font,
                            font_size,
                        } => {
                            if ui.try_get_of_type::<Text>(self.title).is_ok() {
                                // Just modify existing text, this is much faster than
                                // re-create text everytime.
                                ui.send(self.title, TextMessage::Text(text.clone()));
                                if let Some(font) = font {
                                    ui.send(self.title, TextMessage::Font(font.clone()))
                                }
                                if let Some(font_size) = font_size {
                                    ui.send(self.title, TextMessage::FontSize(font_size.clone()));
                                }
                            } else {
                                ui.send(self.title, WidgetMessage::Remove);
                                let font = font.clone().unwrap_or_else(|| ui.default_font.clone());
                                let ctx = &mut ui.build_ctx();
                                self.title = make_text_title(
                                    ctx,
                                    text,
                                    font,
                                    font_size
                                        .clone()
                                        .unwrap_or_else(|| ctx.style.property(Style::FONT_SIZE)),
                                )
                                .to_base();
                                ui.send(self.title, WidgetMessage::link_with(self.title_grid));
                            }
                        }
                        WindowTitle::Node(node) => {
                            if self.title.is_some() {
                                // Remove old title.
                                ui.send(self.title, WidgetMessage::Remove);
                            }

                            if node.is_some() {
                                self.title = *node;

                                // Attach new one.
                                ui.send(self.title, WidgetMessage::link_with(self.title_grid));
                            }
                        }
                    }
                }
                WindowMessage::SafeBorderSize(size) => {
                    if &self.safe_border_size != size {
                        self.safe_border_size = *size;
                        ui.try_send_response(message);
                    }
                }
            }
        }
    }
}

impl Window {
    pub fn tab_label(&self) -> &str {
        &self.tab_label
    }
    pub fn minimized(&self) -> bool {
        self.size_state == WindowSizeState::Minimized
    }
    pub fn maximized(&self) -> bool {
        self.size_state == WindowSizeState::Maximized
    }
    pub fn normal(&self) -> bool {
        self.size_state == WindowSizeState::Normal
    }
    fn update_size_state(&mut self, new_state: WindowSizeState, ui: &mut UserInterface) {
        if self.size_state == new_state {
            return;
        }
        if new_state == WindowSizeState::Maximized && !self.can_resize {
            return;
        }
        let current_size = self.actual_global_size();
        let current_position = self.screen_position();
        match self.size_state {
            WindowSizeState::Normal => {
                self.prev_bounds = Some(Rect::new(
                    current_position.x,
                    current_position.y,
                    current_size.x,
                    current_size.y,
                ));
            }
            WindowSizeState::Minimized => {
                self.prev_bounds = Some(Rect::new(
                    current_position.x,
                    current_position.y,
                    current_size.x,
                    self.prev_bounds.map(|b| b.size.y).unwrap_or(current_size.y),
                ));
            }
            _ => (),
        }
        let new_bounds = match new_state {
            WindowSizeState::Normal | WindowSizeState::Minimized => {
                self.prev_bounds.unwrap_or_else(|| {
                    Rect::new(
                        current_position.x,
                        current_position.y,
                        current_size.x,
                        current_size.y,
                    )
                })
            }
            WindowSizeState::Maximized => Rect::new(0.0, 0.0, ui.screen_size.x, ui.screen_size.y),
        };

        if self.content.is_some() {
            ui.send(
                self.content,
                WidgetMessage::Visibility(new_state != WindowSizeState::Minimized),
            );
        }

        if new_state == WindowSizeState::Minimized {
            self.set_desired_local_position(new_bounds.position);
            if self.can_resize {
                self.set_width(new_bounds.w());
            }
            self.set_height(f32::NAN);
            self.invalidate_layout();
        } else {
            ui.send(
                self.handle,
                WidgetMessage::DesiredPosition(new_bounds.position),
            );
            if self.can_resize {
                ui.send_many(
                    self.handle,
                    [
                        WidgetMessage::Width(new_bounds.w()),
                        WidgetMessage::Height(new_bounds.h()),
                    ],
                );
            }
        }
        self.size_state = new_state;
    }
    /// Checks whether any resizing grip is active or not.
    pub fn has_active_grip(&self) -> bool {
        for grip in self.grips.borrow().iter() {
            if grip.is_dragging {
                return true;
            }
        }
        false
    }

    fn content_to_focus(&self) -> Handle<UiNode> {
        if self.content.is_some() {
            self.content
        } else {
            self.handle
        }
    }

    fn is_docked(&self, ui: &UserInterface) -> bool {
        self.parent() != ui.root_canvas
    }
}

/// Window builder creates [`Window`] instances and adds them to the user interface.
pub struct WindowBuilder {
    /// Base widget builder.
    pub widget_builder: WidgetBuilder,
    /// Content of the window.
    pub content: Handle<UiNode>,
    /// Optional title of the window.
    pub title: Option<WindowTitle>,
    /// Label for the window's tab.
    pub tab_label: String,
    /// Whether the window can be closed or not.
    pub can_close: bool,
    /// Whether the window can be minimized or not.
    pub can_minimize: bool,
    /// Whether the window can be maximized or not.
    pub can_maximize: bool,
    /// Whether the window should be created open or not.
    pub open: bool,
    /// Optional custom closing button, if not specified, then a default button will be created.
    pub close_button: Option<Handle<Button>>,
    /// Optional custom minimization button, if not specified, then a default button will be created.
    pub minimize_button: Option<Handle<Button>>,
    /// Optional custom maximization button, if not specified, then a default button will be created.
    pub maximize_button: Option<Handle<Button>>,
    /// Whether the window should be created as modal or not. Warning: Any independent builders must
    /// take this into account!
    pub modal: bool,
    /// Whether the window should be resizable or not.
    pub can_resize: bool,
    /// Optional size of the border around the screen in which the window will be forced to stay.
    pub safe_border_size: Option<Vector2<f32>>,
    /// If `true`, then the window can be closed using `Esc` key. Default is `true`. Works only if
    /// `can_close` is also `true`.
    pub close_by_esc: bool,
    /// If `true`, then the window will be deleted after closing.
    pub remove_on_close: bool,
}

/// Window title can be either text or node.
///
/// If `Text` is used, then builder will automatically create [`Text`] node with specified text,
/// but with default font.
///
/// If you need more flexibility (i.e. put a picture near text) then [`WindowTitle::Node`] option
/// is for you: it allows to put any UI node hierarchy you want to.
#[derive(Debug, Clone, PartialEq)]
pub enum WindowTitle {
    Text {
        /// Actual text of the title.
        text: String,
        /// Optional font, if [`None`], then the default font will be used.
        font: Option<FontResource>,
        /// Optional size of the text. Default is [`None`] (in this case default size defined by the
        /// current style will be used).
        font_size: Option<StyledProperty<f32>>,
    },
    Node(Handle<UiNode>),
}

impl WindowTitle {
    /// A shortcut to create [`WindowTitle::Text`]
    pub fn text<P: AsRef<str>>(text: P) -> Self {
        WindowTitle::Text {
            text: text.as_ref().to_owned(),
            font: None,
            font_size: None,
        }
    }

    /// A shortcut to create [`WindowTitle::Text`] with custom font.
    pub fn text_with_font<P: AsRef<str>>(text: P, font: FontResource) -> Self {
        WindowTitle::Text {
            text: text.as_ref().to_owned(),
            font: Some(font),
            font_size: None,
        }
    }

    /// A shortcut to create [`WindowTitle::Text`] with custom font and size.
    pub fn text_with_font_size<P: AsRef<str>>(
        text: P,
        font: FontResource,
        size: StyledProperty<f32>,
    ) -> Self {
        WindowTitle::Text {
            text: text.as_ref().to_owned(),
            font: Some(font),
            font_size: Some(size),
        }
    }

    /// A shortcut to create [`WindowTitle::Node`]
    pub fn node(node: Handle<UiNode>) -> Self {
        Self::Node(node)
    }
}

fn make_text_title(
    ctx: &mut BuildContext,
    text: &str,
    font: FontResource,
    size: StyledProperty<f32>,
) -> Handle<Text> {
    TextBuilder::new(
        WidgetBuilder::new()
            .with_margin(Thickness::left(5.0))
            .on_row(0)
            .on_column(0),
    )
    .with_font_size(size)
    .with_font(font)
    .with_vertical_text_alignment(VerticalAlignment::Center)
    .with_horizontal_text_alignment(HorizontalAlignment::Left)
    .with_text(text)
    .build(ctx)
}

enum HeaderButton {
    Close,
    Minimize,
    Maximize,
}

fn make_mark(ctx: &mut BuildContext, button: HeaderButton) -> Handle<VectorImage> {
    let size = 12.0;

    VectorImageBuilder::new(
        WidgetBuilder::new()
            .with_horizontal_alignment(HorizontalAlignment::Center)
            .with_vertical_alignment(match button {
                HeaderButton::Close => VerticalAlignment::Center,
                HeaderButton::Minimize => VerticalAlignment::Bottom,
                HeaderButton::Maximize => VerticalAlignment::Center,
            })
            .with_width(size)
            .with_height(size)
            .with_foreground(ctx.style.property(Style::BRUSH_BRIGHT)),
    )
    .with_primitives(match button {
        HeaderButton::Close => {
            vec![
                Primitive::Line {
                    begin: Vector2::new(0.0, 0.0),
                    end: Vector2::new(size, size),
                    thickness: 1.0,
                },
                Primitive::Line {
                    begin: Vector2::new(size, 0.0),
                    end: Vector2::new(0.0, size),
                    thickness: 1.0,
                },
            ]
        }
        HeaderButton::Minimize => {
            let bottom_spacing = 3.0;

            vec![Primitive::Line {
                begin: Vector2::new(0.0, size - bottom_spacing),
                end: Vector2::new(size, size - bottom_spacing),
                thickness: 1.0,
            }]
        }
        HeaderButton::Maximize => {
            let thickness = 1.25;
            let half_thickness = thickness * 0.5;

            vec![
                Primitive::Line {
                    begin: Vector2::new(0.0, half_thickness),
                    end: Vector2::new(size, half_thickness),
                    thickness,
                },
                Primitive::Line {
                    begin: Vector2::new(size - half_thickness, 0.0),
                    end: Vector2::new(size - half_thickness, size),
                    thickness,
                },
                Primitive::Line {
                    begin: Vector2::new(size, size - half_thickness),
                    end: Vector2::new(0.0, size - half_thickness),
                    thickness,
                },
                Primitive::Line {
                    begin: Vector2::new(half_thickness, size),
                    end: Vector2::new(half_thickness, 0.0),
                    thickness,
                },
            ]
        }
    })
    .build(ctx)
}

fn make_header_button(ctx: &mut BuildContext, button: HeaderButton) -> Handle<Button> {
    ButtonBuilder::new(WidgetBuilder::new().with_margin(Thickness::uniform(2.0)))
        .with_back(
            DecoratorBuilder::new(
                BorderBuilder::new(WidgetBuilder::new())
                    .with_stroke_thickness(Thickness::uniform(0.0).into())
                    .with_pad_by_corner_radius(false)
                    .with_corner_radius(4.0f32.into()),
            )
            .with_normal_brush(Brush::Solid(Color::TRANSPARENT).into())
            .with_hover_brush(ctx.style.property(Style::BRUSH_LIGHT))
            .with_pressed_brush(ctx.style.property(Style::BRUSH_LIGHTEST))
            .build(ctx),
        )
        .with_content(make_mark(ctx, button))
        .build(ctx)
}

impl WindowBuilder {
    /// Creates new window builder.
    pub fn new(widget_builder: WidgetBuilder) -> Self {
        Self {
            widget_builder,
            content: Handle::NONE,
            title: None,
            tab_label: String::default(),
            can_close: true,
            can_minimize: true,
            can_maximize: true,
            open: true,
            close_button: None,
            minimize_button: None,
            maximize_button: None,
            modal: false,
            can_resize: true,
            safe_border_size: Some(Vector2::new(25.0, 20.0)),
            close_by_esc: true,
            remove_on_close: false,
        }
    }

    /// Sets a desired window content.
    pub fn with_content(mut self, content: Handle<impl ObjectOrVariant<UiNode>>) -> Self {
        self.content = content.to_base();
        self
    }

    /// Sets a desired window title.
    pub fn with_title(mut self, title: WindowTitle) -> Self {
        self.title = Some(title);
        self
    }

    pub fn with_tab_label<S: Into<String>>(mut self, label: S) -> Self {
        self.tab_label = label.into();
        self
    }

    /// Sets a desired minimization button.
    pub fn with_minimize_button(mut self, button: Handle<Button>) -> Self {
        self.minimize_button = Some(button);
        self
    }

    /// Sets a desired maximization button.
    pub fn with_maximize_button(mut self, button: Handle<Button>) -> Self {
        self.minimize_button = Some(button);
        self
    }

    /// Sets a desired closing button.
    pub fn with_close_button(mut self, button: Handle<Button>) -> Self {
        self.close_button = Some(button);
        self
    }

    /// Sets whether the window can be closed or not.
    pub fn can_close(mut self, can_close: bool) -> Self {
        self.can_close = can_close;
        self
    }

    /// Sets whether the window can be minimized or not.
    pub fn can_minimize(mut self, can_minimize: bool) -> Self {
        self.can_minimize = can_minimize;
        self
    }

    /// Sets whether the window can be maximized or not.
    pub fn can_maximize(mut self, can_minimize: bool) -> Self {
        self.can_maximize = can_minimize;
        self
    }

    /// Sets whether the window should be open or not.
    pub fn open(mut self, open: bool) -> Self {
        self.open = open;
        self
    }

    /// Sets whether the window should be modal or not.
    pub fn modal(mut self, modal: bool) -> Self {
        self.modal = modal;
        self
    }

    /// Sets whether the window can be resized or not.
    pub fn can_resize(mut self, can_resize: bool) -> Self {
        self.can_resize = can_resize;
        self
    }

    /// Sets a desired safe border size.
    pub fn with_safe_border_size(mut self, size: Option<Vector2<f32>>) -> Self {
        self.safe_border_size = size.map(|s| Vector2::new(s.x.abs(), s.y.abs()));
        self
    }

    /// Defines, whether the window can be closed using `Esc` key or not. Works only if `can_close`
    /// is also `true`.
    pub fn with_close_by_esc(mut self, close: bool) -> Self {
        self.close_by_esc = close;
        self
    }

    /// Defines, whether the window should be deleted after closing or not. Default is `false`.
    pub fn with_remove_on_close(mut self, close: bool) -> Self {
        self.remove_on_close = close;
        self
    }

    /// Finishes window building and returns its instance.
    pub fn build_window(self, ctx: &mut BuildContext) -> Window {
        let minimize_button;
        let maximize_button;
        let close_button;
        let title;
        let title_grid;
        let header = BorderBuilder::new(
            WidgetBuilder::new()
                .with_horizontal_alignment(HorizontalAlignment::Stretch)
                .with_height(22.0)
                .with_background(ctx.style.property(Style::BRUSH_DARKER))
                .with_child({
                    title_grid = GridBuilder::new(
                        WidgetBuilder::new()
                            .with_child({
                                title = match self.title {
                                    None => Handle::NONE,
                                    Some(window_title) => match window_title {
                                        WindowTitle::Node(node) => node,
                                        WindowTitle::Text {
                                            text,
                                            font,
                                            font_size,
                                        } => make_text_title(
                                            ctx,
                                            &text,
                                            font.unwrap_or_else(|| ctx.default_font()),
                                            font_size.unwrap_or_else(|| {
                                                ctx.style.property(Style::FONT_SIZE)
                                            }),
                                        )
                                        .to_base(),
                                    },
                                };
                                title
                            })
                            .with_child({
                                minimize_button = self.minimize_button.unwrap_or_else(|| {
                                    make_header_button(ctx, HeaderButton::Minimize)
                                });
                                ctx[minimize_button]
                                    .set_visibility(self.can_minimize)
                                    .set_width(20.0)
                                    .set_row(0)
                                    .set_column(1);
                                minimize_button
                            })
                            .with_child({
                                maximize_button = self.maximize_button.unwrap_or_else(|| {
                                    make_header_button(ctx, HeaderButton::Maximize)
                                });
                                ctx[maximize_button]
                                    .set_visibility(self.can_maximize)
                                    .set_width(20.0)
                                    .set_row(0)
                                    .set_column(2);
                                maximize_button
                            })
                            .with_child({
                                close_button = self.close_button.unwrap_or_else(|| {
                                    make_header_button(ctx, HeaderButton::Close)
                                });
                                ctx[close_button]
                                    .set_width(20.0)
                                    .set_visibility(self.can_close)
                                    .set_row(0)
                                    .set_column(3);
                                close_button
                            }),
                    )
                    .add_column(Column::stretch())
                    .add_column(Column::auto())
                    .add_column(Column::auto())
                    .add_column(Column::auto())
                    .add_row(Row::stretch())
                    .build(ctx);
                    title_grid
                })
                .on_row(0),
        )
        .with_pad_by_corner_radius(false)
        .with_corner_radius(4.0f32.into())
        .with_stroke_thickness(Thickness::uniform(0.0).into())
        .build(ctx)
        .to_base();

        let border = BorderBuilder::new(
            WidgetBuilder::new()
                .with_foreground(ctx.style.property(Style::BRUSH_DARKER))
                .with_child(
                    GridBuilder::new(
                        WidgetBuilder::new()
                            .with_child(
                                NavigationLayerBuilder::new(
                                    WidgetBuilder::new().on_row(1).with_child(self.content),
                                )
                                .build(ctx),
                            )
                            .with_child(header),
                    )
                    .add_column(Column::stretch())
                    .add_row(Row::auto())
                    .add_row(Row::stretch())
                    .build(ctx),
                ),
        )
        .with_pad_by_corner_radius(false)
        .with_corner_radius(4.0f32.into())
        .with_stroke_thickness(Thickness::uniform(1.0).into())
        .build(ctx);

        Window {
            widget: self
                .widget_builder
                .with_visibility(self.open)
                .with_child(border)
                .build(ctx),
            mouse_click_pos: Vector2::default(),
            initial_position: Vector2::default(),
            initial_size: Default::default(),
            is_dragging: false,
            size_state: WindowSizeState::default(),
            can_minimize: self.can_minimize,
            can_maximize: self.can_maximize,
            can_close: self.can_close,
            can_resize: self.can_resize,
            header,
            tab_label: self.tab_label,
            minimize_button,
            maximize_button,
            close_button,
            drag_delta: Default::default(),
            content: self.content,
            safe_border_size: self.safe_border_size,
            grips: RefCell::new([
                // Corners have priority
                Grip::new(GripKind::LeftTopCorner, CursorIcon::NwResize),
                Grip::new(GripKind::RightTopCorner, CursorIcon::NeResize),
                Grip::new(GripKind::RightBottomCorner, CursorIcon::SeResize),
                Grip::new(GripKind::LeftBottomCorner, CursorIcon::SwResize),
                Grip::new(GripKind::Left, CursorIcon::WResize),
                Grip::new(GripKind::Top, CursorIcon::NResize),
                Grip::new(GripKind::Right, CursorIcon::EResize),
                Grip::new(GripKind::Bottom, CursorIcon::SResize),
            ]),
            title,
            title_grid,
            prev_bounds: None,
            close_by_esc: self.close_by_esc,
            remove_on_close: self.remove_on_close,
        }
    }

    /// Finishes window building and returns its handle.
    pub fn build(self, ctx: &mut BuildContext) -> Handle<Window> {
        let modal = self.modal;
        let open = self.open;

        let node = self.build_window(ctx);
        let handle = ctx.add(node);

        if modal && open {
            ctx.push_picking_restriction(RestrictionEntry {
                handle: handle.to_base(),
                stop: true,
            });
        }

        handle.to_variant()
    }
}

#[cfg(test)]
mod test {
    use crate::window::WindowBuilder;
    use crate::{test::test_widget_deletion, widget::WidgetBuilder};

    #[test]
    fn test_deletion() {
        test_widget_deletion(|ctx| WindowBuilder::new(WidgetBuilder::new()).build(ctx));
    }
}