aboutsummaryrefslogtreecommitdiff
path: root/src/chromeBadge.ts
blob: df12fba8341ba9995cd49cbd57bb8b24f0b8f940 (plain)
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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
/*
 This file is part of TALER
 (C) 2016 INRIA

 TALER is free software; you can redistribute it and/or modify it under the
 terms of the GNU General Public License as published by the Free Software
 Foundation; either version 3, or (at your option) any later version.

 TALER is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along with
 TALER; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
 */

import {
  Badge
} from "./wallet";


/**
 * Polyfill for requestAnimationFrame, which
 * doesn't work from a background page.
 */
function rAF(cb: (ts: number) => void) {
  window.setTimeout(() => {
    cb(performance.now());
  }, 100 /* 100 ms delay between frames */);
}


export class ChromeBadge implements Badge {
  canvas: HTMLCanvasElement;
  ctx: CanvasRenderingContext2D;
  /**
   * True if animation running.  The animation
   * might still be running even if we're not busy anymore,
   * just to transition to the "normal" state in a animated way.
   */
  animationRunning: boolean = false;

  /**
   * Is the wallet still busy? Note that we do not stop the
   * animation immediately when the wallet goes idle, but
   * instead slowly close the gap.
   */
  isBusy: boolean = false;

  /**
   * Current rotation angle, ranges from 0 to rotationAngleMax.
   */
  rotationAngle: number = 0;

  /**
   * While animating, how wide is the current gap in the circle?
   * Ranges from 0 to openMax.
   */
  gapWidth: number = 0;

  /**
   * Maximum value for our rotationAngle, corresponds to 2 Pi.
   */
  static rotationAngleMax = 1000;

  /**
   * How fast do we rotate?  Given in rotation angle (relative to rotationAngleMax) per millisecond.
   */
  static rotationSpeed = 0.5;

  /**
   * How fast to we open?  Given in rotation angle (relative to rotationAngleMax) per millisecond.
   */
  static openSpeed = 0.15;

  /**
   * How fast to we close?  Given as a multiplication factor per frame update.
   */
  static closeSpeed = 0.7;

  /**
   * How far do we open? Given relative to rotationAngleMax.
   */
  static openMax = 100;

  constructor(window?: Window) {
    // Allow injecting another window for testing
    let bg = window || chrome.extension.getBackgroundPage();
    if (!bg) {
      throw Error("no window available");
    }
    this.canvas = bg.document.createElement("canvas");
    // Note: changing the width here means changing the font
    // size in draw() as well!
    this.canvas.width = 32;
    this.canvas.height = 32;
    this.ctx = this.canvas.getContext("2d")!;
    this.draw();
  }

  /**
   * Draw the badge based on the current state.
   */
  private draw() {
    this.ctx.setTransform(1, 0, 0, 1, 0, 0);
    this.ctx.clearRect(0, 0, this.canvas.width, this.canvas.height);

    this.ctx.translate(this.canvas.width / 2, this.canvas.height / 2);

    this.ctx.beginPath();
    this.ctx.arc(0, 0, this.canvas.width / 2 - 2, 0, 2 * Math.PI);
    this.ctx.fillStyle = "white";
    this.ctx.fill();

    // move into the center, off by 2 for aligning the "T" with the bottom
    // of the circle.
    this.ctx.translate(0, 2);

    // pick sans-serif font; note: 14px is based on the 32px width above!
    this.ctx.font = "bold 24px sans-serif";
    // draw the "T" perfectly centered (x and y) to the current position
    this.ctx.textAlign = "center";
    this.ctx.textBaseline = "middle";
    this.ctx.fillStyle = "black";
    this.ctx.fillText("T", 0, 0);
    // now move really into the center
    this.ctx.translate(0, -2);
    // start drawing the (possibly open) circle
    this.ctx.beginPath();
    this.ctx.lineWidth = 2.5;
    if (this.animationRunning) {
      /* Draw circle around the "T" with an opening of this.gapWidth */
      this.ctx.arc(0, 0,
                   this.canvas.width / 2 - 2, /* radius */
                   this.rotationAngle / ChromeBadge.rotationAngleMax * Math.PI * 2,
                   ((this.rotationAngle + ChromeBadge.rotationAngleMax - this.gapWidth) / ChromeBadge.rotationAngleMax) * Math.PI * 2,
                   false);
    }
    else {
      /* Draw full circle */
      this.ctx.arc(0, 0,
                   this.canvas.width / 2 - 2, /* radius */
                   0,
                   Math.PI * 2,
                   false);
    }
    this.ctx.stroke();
    // go back to the origin
    this.ctx.translate(-this.canvas.width / 2, -this.canvas.height / 2);

    // Allow running outside the extension for testing
    if (window["chrome"] && window.chrome["browserAction"]) {
      let imageData = this.ctx.getImageData(0,
                                            0,
                                            this.canvas.width,
                                            this.canvas.height);
      chrome.browserAction.setIcon({imageData});
    }
  }

  private animate() {
    if (this.animationRunning) {
      return;
    }
    this.animationRunning = true;
    let start: number|undefined = undefined;
    let step = (timestamp: number) => {
      if (!this.animationRunning) {
        return;
      }
      if (!start) {
        start = timestamp;
      }
      let delta = (timestamp - start);
      if (!this.isBusy && 0 == this.gapWidth) {
        // stop if we're close enough to origin
        this.rotationAngle = 0;
      } else {
        this.rotationAngle = (this.rotationAngle + (timestamp - start) * ChromeBadge.rotationSpeed) % ChromeBadge.rotationAngleMax;
      }
      if (this.isBusy) {
        if (this.gapWidth < ChromeBadge.openMax) {
          this.gapWidth += ChromeBadge.openSpeed * (timestamp - start);
        }
        if (this.gapWidth > ChromeBadge.openMax) {
          this.gapWidth = ChromeBadge.openMax;
        }
      }
      else {
        if (this.gapWidth > 0) {
          this.gapWidth--;
          this.gapWidth *= ChromeBadge.closeSpeed;
        }
      }


      if (this.isBusy || this.gapWidth > 0) {
        start = timestamp;
        rAF(step);
      } else {
        this.animationRunning = false;
      }
      this.draw();
    };
    rAF(step);
  }

  setText(s: string) {
    chrome.browserAction.setBadgeText({text: s});
  }

  setColor(c: string) {
    chrome.browserAction.setBadgeBackgroundColor({color: c});
  }

  startBusy() {
    if (this.isBusy) {
      return;
    }
    this.isBusy = true;
    this.animate();
  }

  stopBusy() {
    this.isBusy = false;
  }
}