@@ -0,0 +1,63 @@ +(function(){ + /** + * @private + * @method iterateData + * @param {CanvasRenderingContext2D} ctx context to test + * @param {Function} fn Callback, invoked with `currentValue`, `previousValue` and `index`. + * Breaks out of the loop if callback returns `false`. + */ + function iterateData(ctx, fn) { + var data = ctx.getImageData(0, 0, ctx.canvas.width, ctx.canvas.height).data; + for (var i = data.length; i--; ) { + if (i > 4) { + if (fn(data[i], data[i - 4], i) === false) break; + } + } + } + + /** + * @method assertColor + * @param {CanvasRenderingContext2D} ctx context to test + * @param {String} color color in a hex value + * @return {Boolean | null} `true` if all canvas pixels are of a given color, `null` if wrong color is given + * @example `assertColor(canvas._oContextContainer, 'ff5555');` + */ + function assertColor(ctx, color) { + var match, r, g, b; + if (match = String(color).match(/^#?([a-f0-9]{2})([a-f0-9]{2})([a-f0-9]{2})$/i)) { + r = parseInt(match[1], 16); + g = parseInt(match[2], 16); + b = parseInt(match[3], 16); + } + else return null; + var result = true; + iterateData(ctx, function(currentValue, prevValue, i) { + if ((!(i % 4) && (currentValue !== r)) || + (!((i-1) % 4) && (currentValue !== g)) || + (!((i-2) % 4) && (currentValue !== b))) { + return (result = false); + } + }); + return result; + } + + /** + * @method assertSameColor + * @param {CanvasRenderingContext2D} ctx context to test + * @return {Boolean} `true` if all canvas pixels are of the same color + * @example `assertSameColor(canvas._oContextContainer);` + */ + function assertSameColor(ctx) { + var result = true; + iterateData(ctx, function(currentValue, prevValue, i) { + if (currentValue !== prevValue) { + return (result = false); + } + }); + return result; + } + + // export as global + this.assertColor = assertColor; + this.assertSameColor = assertSameColor; +})(); \ No newline at end of file canvas_assertions.js 5c1da6016b51fdc8edb3b188855ca310b00ec257 Juriy Zaytsev juriy@kangax.local http://github.com/kangax/protolicious/commit/889a60d6d22cd59e93664ae04866e245c89b35aa 889a60d6d22cd59e93664ae04866e245c89b35aa 2009-04-24T09:17:05-07:00 2009-04-24T09:17:05-07:00 Add `assertColor` and `assertSameColor`. fc5f7e1f9faaee7798c10e160e72d3a0dd04714a Juriy Zaytsev juriy@kangax.local