IE < 10 does not support gradients.

Tom

2014-11-17 3f6995c70e8b15f7abf1785eb780a0de46f8bd07

IE < 10 does not support gradients.

Since the new imgdiff UI heavily used gradients, this leaves IE9 and
IE8 users with a complete disfunctional UI.

Replaced all gradients by simpler means:

* Vertical handle: instead of 2px wide gradient, use a 1px background
  and a white border-right
  
* Opacity slider: No gradient but a simple border and background-color

* All radial-gradients replaced by small pre-computed PNGs

* Checkerboard background done with a small repeated PNG

With these changes, the imgdiff UI is fully functional even in IE 8.
Visual changes in other browsers are barely discernible.

 src/main/resources/gitblit.css

@@ -1440,6 +1440,8 @@


/* Image diffs. */



/* Note: can't use gradients; IE < 10 doesn't support them. Use pre-created pngs with transparency instead. */



/* Set on body during mouse tracking. */

.no-select {

    -webkit-touch-callout:none;

@@ -1460,10 +1462,14 @@
    position:relative;

    display: inline-block;

    /* Checkerboard background to reveal transparency. */

    background-color: white;

    background-image: linear-gradient(45deg, #DDD 25%, transparent 25%, transparent 75%, #DDD 75%, #DDD), linear-gradient(45deg, #DDD 25%, transparent 25%, transparent 75%, #DDD 75%, #DDD);

    background-size:16px 16px;

    background-position:0 0, 8px 8px;

    background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAIAAACQkWg2AAAACXBIWXMAAAsTAAALEwEAmpwYAAAAK0lEQVQoz2O8e/cuAzagpKSEVZyJgUQwqoEYwPj//3+sEvfu3RsNJfppAACQZwizxs5QrAAAAABJRU5ErkJggg==);

    background-repeat: repeat;

    /* Same with CSS:

    background-color: white;

    background-image: linear-gradient(45deg, #DDD 25%, transparent 25%, transparent 75%, #DDD 75%, #DDD), linear-gradient(45deg, #DDD 25%, transparent 25%, transparent 75%, #DDD 75%, #DDD);

    background-size:16px 16px;

    background-position:0 0, 8px 8px;

    */

}



div.imgdiff-left {

@@ -1490,9 +1496,8 @@
    margin: 12px 35px;

    padding: 0;

    position: relative;

    border-left: 1px solid #888;

    border-right: 1px solid #888;

    background: linear-gradient(to bottom, #888, #EEE 50%, #888);

    border: 1px solid #888;

    background-color: #DDD;

}



.imgdiff-opa-container:before {

@@ -1502,7 +1507,8 @@
    top: -4px;

    width : 12px;

    height: 12px;

    background-image: radial-gradient(6px at 50% 50%, rgba(255, 255, 255, 255) 50%, rgba(255, 255, 255, 0) 6px);

    background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAAMCAYAAABWdVznAAAACXBIWXMAAAsTAAALEwEAmpwYAAAA7klEQVQoz13STUrDMRAF8N+02fQDhCpqNyJIvUEXXfYCXtlFsZeQLpRCpYJ01RakxM38IRgIQyZv3rx5SchVaw1c4xm36OEb7/jqcJHgPuZYYopx3h2xwwrriPgtyTzHCx5xg1ESnvJ8lR1fS8pYJvgBEwyywwlD9LGotX6W1DxNpknutkPgnGSzkgOOEzRoogY8zPx9L7VFa0Ku//lAlLTumO1PjYxuhnMT9yV93uUMw2Q+NwU/OGCL95KPskrr+o3mruCAD7xhU1LjOpkX6caoGXib4HVEXKLWKiK67/GEGe6SYJ+SNxFxqbX2/gBxKkhxx1tQIAAAAABJRU5ErkJggg==);

    /* With CSS: background-image: radial-gradient(6px at 50% 50%, rgba(255, 255, 255, 255) 50%, rgba(255, 255, 255, 0) 6px); */

}



.imgdiff-opa-container:after {

@@ -1512,7 +1518,8 @@
    top: -4px;

    width : 12px;

    height: 12px;

    background-image: radial-gradient(6px at 50% 50%, #888, #888 1px, transparent 6px);

    background-image: url(data:image/png;base64,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);

    /* With CSS: background-image: radial-gradient(6px at 50% 50%, #888, #888 1px, transparent 6px); */

}



.imgdiff-opa-slider {

@@ -1529,7 +1536,8 @@
    height: 10px;

    position: absolute;

    top: -3px;

    background-image: radial-gradient(5px at 50% 50%, #444, #888, transparent 5px);

    background-image: url(data:image/png;base64,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);

    /* With CSS: background-image: radial-gradient(5px at 50% 50%, #444, #888, transparent 5px); */

}



.imgdiff-ovr-slider {

@@ -1541,10 +1549,11 @@
}



.imgdiff-ovr-handle {

    width : 2px;

    width : 1px;

    height: 100%;

    top: 0px;

    background: linear-gradient(to right, #444, #FFF);

    background-color: #444;

    border-right: 1px solid #FFF;

}



.imgdiff-ovr-handle:before {

@@ -1554,7 +1563,8 @@
    bottom: -5px;

    width : 10px;

    height: 10px;

    background-image: radial-gradient(5px at 50% 50%, #444, #888, transparent 5px);

    background-image: url(data:image/png;base64,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);

    /* With CSS: background-image: radial-gradient(5px at 50% 50%, #444, #888, transparent 5px); */

}



.imgdiff-ovr-handle:after {

@@ -1564,8 +1574,8 @@
    top: -5px;

    width : 10px;

    height: 10px;

    /* border: 1px solid red; */

    background-image: radial-gradient(5px at 50% 50%, #444, #888, transparent 5px);

    background-image: url(data:image/png;base64,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);

    /* With CSS: background-image: radial-gradient(5px at 50% 50%, #444, #888, transparent 5px); */

}



/* End image diffs */