| <!DOCTYPE html> |
| <style> |
| .spacer { |
| height: 1000px; |
| width: 1000px; |
| } |
| #scroller, body { |
| height: 100px; |
| width: 100px; |
| overflow: scroll; |
| } |
| |
| </style> |
| <body class=scroller> |
| <div id=console></div> |
| |
| <div id=scroller> |
| <div class=spacer></div> |
| </div> |
| <div class=spacer></div> |
| </body> |
| |
| <script src="../../resources/js-test.js"></script> |
| <script> |
| |
| description("Verifies that scrolling APIs support fractional offsets."); |
| // Note we current support fractional scrolling only for the special case of |
| // browser zoom. When http://crbug.com/414283 is fixed, we should test |
| // other cases like device scale. |
| |
| // FIXME: Make this smaller. crbug.com/414283. |
| var floatPrecision = 0.01; |
| |
| function testScroll(scrollOffset, expectedScrollOffset) { |
| |
| debug('Scrolling DIV with scrollTop/scrollLeft'); |
| scroller.scrollTop = scrollOffset; |
| shouldBeCloseTo('scroller.scrollTop', expectedScrollOffset, floatPrecision); |
| scroller.scrollLeft = scrollOffset; |
| shouldBeCloseTo('scroller.scrollLeft', expectedScrollOffset, floatPrecision); |
| |
| // Note that the body element is a special case - we don't attempt to |
| // test it here as it's semantics are in flux (http://goo.gl/BFHtMR). |
| |
| debug('Scrolling the document with window.scroll'); |
| window.scroll(0,0); |
| scrollOffset++; |
| expectedScrollOffset++; |
| window.scroll(scrollOffset, scrollOffset); |
| shouldBeCloseTo('window.scrollY', expectedScrollOffset, floatPrecision); |
| shouldBeCloseTo('window.scrollX', expectedScrollOffset, floatPrecision); |
| |
| debug('Scrolling the document with window.scrollTo'); |
| window.scroll(0,0); |
| window.scrollTo(scrollOffset, scrollOffset); |
| shouldBeCloseTo('window.pageYOffset', expectedScrollOffset, floatPrecision); |
| shouldBeCloseTo('window.pageXOffset', expectedScrollOffset, floatPrecision); |
| |
| debug('Scrolling the document with window.scrollBy'); |
| window.scroll(1,1); |
| window.scrollBy(scrollOffset - 1, scrollOffset - 1); |
| shouldBeCloseTo('window.scrollY', expectedScrollOffset, floatPrecision); |
| shouldBeCloseTo('window.scrollX', expectedScrollOffset, floatPrecision); |
| |
| debug(''); |
| } |
| |
| function testPageZoom(zoom) { |
| debug('---- Testing page zoom = ' + zoom + ' ----'); |
| eventSender.setPageZoomFactor(zoom); |
| testScroll(4, 4); |
| testScroll(4.5, 4.5); |
| } |
| |
| debug("set PreferCompositingToLCDTextEnabled true"); |
| window.internals.settings.setPreferCompositingToLCDTextEnabled(true); |
| testScroll(4.2, 4.2); |
| testPageZoom(2); |
| |
| // If there is no browser zoom, floating point scroll offsets are truncated. |
| // If there is browser zoom, we can still get fractional scroll offsets |
| // through JS. |
| debug("set PreferCompositingToLCDTextEnabled false"); |
| window.internals.settings.setPreferCompositingToLCDTextEnabled(false); |
| testScroll(4.2, 4); |
| testPageZoom(2); |
| </script> |
