| function waitForWindowScrollEnd(end_x, end_y) { |
| var last_changed_frame = 0; |
| var last_x = scrollX; |
| var last_y = scrollY; |
| return new Promise((resolve, reject) => { |
| function tick(frames) { |
| // We requestAnimationFrames until 20 frames without observed changes or |
| // until the window has scolled to the specified destination. |
| if (frames - last_changed_frame > 20) { |
| resolve(); |
| } |
| if (!(isNaN(end_x) && isNaN(end_y))) { |
| if ((isNaN(end_x) || scrollX == end_x) && |
| (isNaN(end_y) || scrollY == end_y)) { |
| console.log(scrollY + "==" + end_y); |
| resolve(); |
| } |
| } |
| if (window.scrollX != last_x || window.scrollY != last_y) { |
| last_changed_frame = frames; |
| last_x = scrollX; |
| last_y = scrollY; |
| } |
| requestAnimationFrame(tick.bind(null, frames + 1)); |
| } |
| tick(0); |
| }); |
| } |
