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// Pushrod Widgets // Cache // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. use crate::properties::{ WidgetProperties, PROPERTY_BORDER_WIDTH, PROPERTY_FONT_COLOR, PROPERTY_FONT_NAME, PROPERTY_FONT_SIZE, PROPERTY_FONT_STYLE, PROPERTY_HIDDEN, PROPERTY_ID, PROPERTY_INVALIDATED, PROPERTY_NEEDS_LAYOUT, PROPERTY_TEXT, }; use crate::system_widgets::base_widget::BaseWidget; use crate::widget::Widget; use sdl2::image::LoadTexture; use sdl2::pixels::Color; use sdl2::rect::Rect; use sdl2::render::{Canvas, Texture, TextureQuery}; use sdl2::ttf::{FontStyle, Sdl2TtfContext}; use sdl2::video::Window; use std::cell::{RefCell, RefMut}; use std::collections::HashMap; use std::path::Path; struct WidgetCacheContainer { widget: RefCell<Box<dyn Widget>>, _name: String, parent: u32, children: Vec<u32>, } impl WidgetCacheContainer { pub fn new(widget: Box<dyn Widget>, name: String, parent: u32) -> Self { Self { widget: RefCell::new(widget), _name: name, parent, children: Vec::new(), } } } /// This is the `WidgetCache` store structure. pub struct WidgetCache { // TODO cache should be BTreeMap<i32, WidgetCacheContainer> cache: Vec<WidgetCacheContainer>, texture_cache: TextureCache, } /// This is the `WidgetCache` that is used to store `Widget` references in a drawing tree by ID. impl WidgetCache { /// Creates a new `WidgetCache`, adding the `BaseWidget` to the top level of the Window, with the name /// `root` as the root `Widget`. This `Widget` can be modified like any other - its properties /// can be changed, background color, border color, etc. can all be manipulated just like any /// other `Widget`. Its ID is `0`. pub fn new(w: u32, h: u32) -> Self { let mut base_widget = BaseWidget::default(); base_widget .properties() .set_bounds(w, h) .set_origin(0, 0) .invalidate(); Self { cache: vec![WidgetCacheContainer::new( Box::new(base_widget), String::from("root"), 0, )], texture_cache: TextureCache::default(), } } /// Retrieves the ID of the widget at the X/Y coordinates given. /// /// Follows the following rules: /// - If the object is hidden, any objects underneath that object are short-circuited /// - If an object is visible, it walks the object's children to see if they are within the same /// given coordinates /// /// The found ID is then returned having met all of those criteria. If no ID was found, a /// 0 value (root level widget) is returned. #[inline] pub fn id_at_point(&self, x: u32, y: u32) -> u32 { let mut found_id: u32 = 0; let mut hidden_widgets: Vec<u32> = vec![]; let cache_size = self.size(); for id in 0..cache_size { let is_hidden = self.cache[id as usize] .widget .borrow_mut() .properties() .get_bool(PROPERTY_HIDDEN); let widget_xy = self.cache[id as usize] .widget .borrow_mut() .properties() .get_origin(); let widget_wh = self.cache[id as usize] .widget .borrow_mut() .properties() .get_bounds(); if !is_hidden { if x >= widget_xy.0 && x <= widget_xy.0 + widget_wh.0 && y >= widget_xy.1 && y <= widget_xy.1 + widget_wh.1 && !hidden_widgets.contains(&id) { found_id = id; } } else { hidden_widgets.push(id); for hidden_widget_id in self.get_children_of(id) { hidden_widgets.push(hidden_widget_id); } } } found_id } /// Retrieves the `Widget` stored by its `RefMut<Box>` reference. This is a mutable reference /// to the `Widget`, allowing for its properties and other accessors to be immutably changed. #[inline] pub fn get(&self, widget_id: u32) -> RefMut<Box<dyn Widget>> { self.cache[widget_id as usize].widget.borrow_mut() } /// Retrieves the `Widget` stored by its `RefMut<Box>` reference. This is a mutable reference /// to the `Widget`, allowing for its properties and other accessors to be mutably changed. #[inline] pub fn get_mut(&mut self, widget_id: u32) -> RefMut<Box<dyn Widget>> { self.cache[widget_id as usize].widget.borrow_mut() } /// Retrieves the parent ID of the widget ID specified. If the widget is a top level widget (meaning /// there are no additional parents), a 0 will be returned. #[inline] pub fn get_parent_of(&self, widget_id: u32) -> u32 { self.cache[widget_id as usize].parent } /// Retrieves a list of children for the specified widget ID. The child listing will always /// return a `Vec` - if any widgets have been added to this `Widget` as a parent, those IDs /// will be returned here. If this widget has no children, an empty `Vec` will be returned. #[inline] pub fn get_children_of(&self, widget_id: u32) -> Vec<u32> { self.cache[widget_id as usize].children.clone() } /// Adds a new `Widget` to the cache, with the given mutable `Widget`, a name for the `Widget`, /// and the `Widget`'s parent ID. #[inline] pub fn add(&mut self, mut widget: Box<dyn Widget>, widget_name: String, parent_id: u32) -> u32 { // use get_by_name to make sure the widget doesn't already exist by name. If it does, // throw an error. // Invalidate the Widget just in case. widget.invalidate(); self.cache .push(WidgetCacheContainer::new(widget, widget_name, parent_id)); let widget_id = self.size() - 1; self.cache[parent_id as usize].children.push(widget_id); self.cache[widget_id as usize] .widget .borrow_mut() .properties() .set_value(PROPERTY_ID, widget_id as i32); widget_id } /// Adds a list of `Widget`s, storing the IDs resulting from each add, to the parent ID. pub fn add_vec(&mut self, widgets: Vec<Box<dyn Widget>>, parent_id: u32) -> Vec<u32> { let mut return_vec: Vec<u32> = Vec::new(); for widget in widgets { return_vec.push(self.add(widget, format!("widget{}", self.size() - 1), parent_id)); } return_vec } /// Retrieves the total number of `Widget`s in the cache. #[inline] pub fn size(&self) -> u32 { self.cache.len() as u32 } /// Sets the `Widget` ID's `PROPERTY_HIDDEN` value to true/false based on the `state` specified. /// Walks the child IDs of each of the `Widget`'s children and hides their IDs. Does not allow /// for the root ID (`widget_id == 0`) to be hidden. #[inline] pub fn set_hidden(&mut self, widget_id: u32, state: bool) { if widget_id == 0 { return; } if !state { self.get(widget_id).hide(); } else { self.get(widget_id).show(); } let children = self.get_children_of(widget_id); for child_widget_id in children { self.set_hidden(child_widget_id, state); } } /// Determines whether any of the `Widget`s in the cache have indicated that they need to be /// redrawn. #[inline] pub fn invalidated(&self) -> bool { for x in &self.cache { if x.widget.borrow_mut().invalidated() { return true; } } false } /// Determines whether any of the `Widget`s in the cache have indicated that they need to extend /// a layout to the `WidgetCache`. #[inline] pub fn needs_layout(&self) -> bool { for x in &self.cache { if x.widget .borrow_mut() .properties() .get_bool(PROPERTY_NEEDS_LAYOUT) { return true; } } false } fn paint_widget(&mut self, widget_id: u32, c: &mut Canvas<Window>) { let paint_widget = &mut self.cache[widget_id as usize]; let is_hidden = paint_widget .widget .borrow_mut() .properties() .get_bool(PROPERTY_HIDDEN); let widget_xy = paint_widget.widget.borrow_mut().properties().get_origin(); let widget_wh = paint_widget.widget.borrow_mut().properties().get_bounds(); if !is_hidden { match paint_widget .widget .borrow_mut() .draw(c, &mut self.texture_cache) { Some(texture) => { c.copy( texture, None, Rect::new( widget_xy.0 as i32, widget_xy.1 as i32, widget_wh.0, widget_wh.1, ), ) .unwrap(); } None => eprintln!("No texture presented: ID={}", widget_id), }; paint_widget .widget .borrow_mut() .properties() .delete(PROPERTY_INVALIDATED); } } /// Recursive drawing function that takes a `Widget`'s ID, and gets a list of the children that /// are owned for that `Widget`. It then walks the tree of all of the children, and draws the /// contents into a `Texture`. The `TextureCache` is sent such that the `Widget` has the ability /// to load in an image, or render a font. This cache should be used sparingly. /// /// If a draw method is called on a `Widget` but the `Widget` has not been invalidated (meaning /// it does not to be redrawn), the cached `Texture` for the `Widget`'s draw surface is returned, /// which is a reference to an `SDL2 Texture`. This way, the image from GPU memory is simply /// copied back to screen in a very quick operation. /// /// Any `Widget`s that have a property of `PROPERTY_HIDDEN` set will short circuit the draw /// for that `Widget` and its children. /// /// Drawing is computed off-screen in GPU memory, so this is also a very fast operation, which /// should theoretically take place in less than a single draw frame. fn draw(&mut self, widget_id: u32, c: &mut Canvas<Window>) { let children_of_widget = self.get_children_of(widget_id); if children_of_widget.is_empty() { return; } for id in &children_of_widget { self.paint_widget(*id, c); if *id != widget_id { self.draw(*id, c); } } } /// Redraws the screen, redrawing any `Widget`s that have been invalidated, and copying their /// `Texture`s to the screen if necessary. If none of the `Widget`s have been invalidated, /// the screen already contains the main `Texture` with all of the objects, so it does not /// make sense to run this method if the screen does not need refreshing. pub fn refresh(&mut self, c: &mut Canvas<Window>) { // Clear the canvas first. c.set_draw_color(Color::RGBA(255, 255, 255, 255)); c.clear(); self.paint_widget(0, c); self.draw(0, c); // Then swap the canvas once the draw is complete. c.present(); } } /// This is a storage object for the `TextureCache`. pub struct TextureCache { images: HashMap<String, Texture>, ttf_context: Sdl2TtfContext, } /// Default implementation for TextureCache. impl Default for TextureCache { fn default() -> Self { Self { images: HashMap::new(), ttf_context: sdl2::ttf::init().map_err(|e| e.to_string()).unwrap(), } } } /// The `TextureCache` provides a mechanism for caching images, and returning the current /// text rendering context. impl TextureCache { /// Returns the currently available text context as a reference. pub fn get_ttf_context(&self) -> &Sdl2TtfContext { &self.ttf_context } /// Returns an image loaded into a `Texture` reference, caching it in memory. pub fn get_image(&mut self, c: &mut Canvas<Window>, image_name: String) -> &Texture { self.images.entry(image_name.clone()).or_insert({ c.texture_creator() .load_texture(Path::new(&image_name)) .unwrap() }) } /// Renders text, given the font name, size, style, color, string, and max width. Transfers /// ownership of the `Texture` to the calling function, returns the width and height of the /// texture after rendering. By using the identical font name, size, and style, if SDL2 caches /// the font data, this will allow the font to be cached internally. pub fn render_text( &mut self, c: &mut Canvas<Window>, properties: &mut WidgetProperties, alt_color: Option<Color>, ) -> (Texture, u32, u32) { let ttf_context = self.get_ttf_context(); let texture_creator = c.texture_creator(); let bounds = properties.get_bounds(); let font_name = properties.get(PROPERTY_FONT_NAME); let text_color = alt_color.unwrap_or_else(|| properties.get_color(PROPERTY_FONT_COLOR, Color::BLACK)); let font_size = properties.get_value(PROPERTY_FONT_SIZE); let border_width = properties.get_value(PROPERTY_BORDER_WIDTH); let font_style: FontStyle = FontStyle::from_bits_truncate(properties.get_value(PROPERTY_FONT_STYLE)); let text_message = properties.get(PROPERTY_TEXT); let mut font = ttf_context .load_font(Path::new(&font_name), font_size as u16) .unwrap(); let text_max_width = bounds.0; let surface = font .render(&text_message) .blended_wrapped(text_color, text_max_width - (border_width * 2) as u32) .map_err(|e| e.to_string()) .unwrap(); let font_texture = texture_creator .create_texture_from_surface(&surface) .map_err(|e| e.to_string()) .unwrap(); let TextureQuery { width, height, .. } = font_texture.query(); font.set_style(font_style); (font_texture, width, height) } }