gate 0.6.3

A specialized 2D game library
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

// Copyright 2017-2019 Matthew D. Michelotti
//
// 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 std::collections::HashSet;

use sdl2::{
    EventPump,
    event::Event,
    keyboard::Keycode as SdlKeyCode,
    mouse::MouseButton,
};

use crate::{App, AppContext};
use crate::asset_id::AppAssetId;
use crate::input::KeyCode;
use crate::renderer::Renderer;

pub struct EventHandler {
    pump: EventPump,
    held_keys: HashSet<KeyCode>,
}

impl EventHandler {
    pub fn new(pump: EventPump) -> EventHandler {
        EventHandler { pump, held_keys: HashSet::new() }
    }

    pub fn process_events<AS: AppAssetId, AP: App<AS>>(&mut self, app: &mut AP, ctx: &mut AppContext<AS>,
                                                       renderer: &Renderer<AS>) -> bool {
        for event in self.pump.poll_iter() {
            match event {
                Event::Quit { .. } => ctx.close(),
                Event::KeyDown { keycode: Some(keycode), .. } => {
                    if let Some(keycode) = sdl_to_gate_key(keycode) {
                        if self.held_keys.insert(keycode) {
                            app.key_down(keycode, ctx);
                        }
                    }
                },
                Event::KeyUp { keycode: Some(keycode), .. } => {
                    if let Some(keycode) = sdl_to_gate_key(keycode) {
                        if self.held_keys.remove(&keycode) {
                            app.key_up(keycode, ctx);
                        }
                    }
                },
                Event::MouseMotion { x, y, .. } => ctx.set_cursor(renderer.to_app_pos(x, y)),
                Event::MouseButtonDown { x, y, mouse_btn, .. } => {
                    ctx.set_cursor(renderer.to_app_pos(x, y));
                    if let Some(keycode) = mouse_button_to_gate_key(mouse_btn) {
                        if self.held_keys.insert(keycode) {
                            app.key_down(keycode, ctx);
                        }
                    }
                },
                Event::MouseButtonUp { x, y, mouse_btn, .. } => {
                    ctx.set_cursor(renderer.to_app_pos(x, y));
                    if let Some(keycode) = mouse_button_to_gate_key(mouse_btn) {
                        if self.held_keys.remove(&keycode) {
                            app.key_up(keycode, ctx);
                        }
                    }
                },
                _ => {},
            }
            if ctx.take_close_request() { return false; }
        }
        true
    }
}

fn sdl_to_gate_key(sdl: SdlKeyCode) -> Option<KeyCode> {
    match sdl {
        SdlKeyCode::A => Some(KeyCode::A),
        SdlKeyCode::B => Some(KeyCode::B),
        SdlKeyCode::C => Some(KeyCode::C),
        SdlKeyCode::D => Some(KeyCode::D),
        SdlKeyCode::E => Some(KeyCode::E),
        SdlKeyCode::F => Some(KeyCode::F),
        SdlKeyCode::G => Some(KeyCode::G),
        SdlKeyCode::H => Some(KeyCode::H),
        SdlKeyCode::I => Some(KeyCode::I),
        SdlKeyCode::J => Some(KeyCode::J),
        SdlKeyCode::K => Some(KeyCode::K),
        SdlKeyCode::L => Some(KeyCode::L),
        SdlKeyCode::M => Some(KeyCode::M),
        SdlKeyCode::N => Some(KeyCode::N),
        SdlKeyCode::O => Some(KeyCode::O),
        SdlKeyCode::P => Some(KeyCode::P),
        SdlKeyCode::Q => Some(KeyCode::Q),
        SdlKeyCode::R => Some(KeyCode::R),
        SdlKeyCode::S => Some(KeyCode::S),
        SdlKeyCode::T => Some(KeyCode::T),
        SdlKeyCode::U => Some(KeyCode::U),
        SdlKeyCode::V => Some(KeyCode::V),
        SdlKeyCode::W => Some(KeyCode::W),
        SdlKeyCode::X => Some(KeyCode::X),
        SdlKeyCode::Y => Some(KeyCode::Y),
        SdlKeyCode::Z => Some(KeyCode::Z),
        SdlKeyCode::Num0 => Some(KeyCode::Num0),
        SdlKeyCode::Num1 => Some(KeyCode::Num1),
        SdlKeyCode::Num2 => Some(KeyCode::Num2),
        SdlKeyCode::Num3 => Some(KeyCode::Num3),
        SdlKeyCode::Num4 => Some(KeyCode::Num4),
        SdlKeyCode::Num5 => Some(KeyCode::Num5),
        SdlKeyCode::Num6 => Some(KeyCode::Num6),
        SdlKeyCode::Num7 => Some(KeyCode::Num7),
        SdlKeyCode::Num8 => Some(KeyCode::Num8),
        SdlKeyCode::Num9 => Some(KeyCode::Num9),
        SdlKeyCode::Right => Some(KeyCode::Right),
        SdlKeyCode::Left => Some(KeyCode::Left),
        SdlKeyCode::Down => Some(KeyCode::Down),
        SdlKeyCode::Up => Some(KeyCode::Up),
        SdlKeyCode::Return => Some(KeyCode::Return),
        SdlKeyCode::Space => Some(KeyCode::Space),
        SdlKeyCode::Backspace => Some(KeyCode::Backspace),
        SdlKeyCode::Delete => Some(KeyCode::Delete),
        _ => None,
    }
}

fn mouse_button_to_gate_key(button: MouseButton) -> Option<KeyCode> {
    match button {
        MouseButton::Left => Some(KeyCode::MouseLeft),
        MouseButton::Right => Some(KeyCode::MouseRight),
        MouseButton::Middle => Some(KeyCode::MouseMiddle),
        _ => None,
    }
}