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Merged
merged 2 commits into from
Jan 22, 2019
Merged

Add styling API #2

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5c40431
Provide the ability to pass styleOptions to processCues
cobarx Jan 19, 2019
c76400a
Document style options change to processCues
cobarx Jan 19, 2019
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7 changes: 5 additions & 2 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -176,16 +176,19 @@ nodes attached to a top level div.
var div = WebVTT.convertCueToDOMTree(window, cuetext);
```

## WebVTT.processCues(window, cues, overlay)
## WebVTT.processCues(window, cues, overlay, options)

Converts the cuetext of the cues passed to it to DOM trees—by calling convertCueToDOMTree—and
then runs the processing model steps of the WebVTT specification on the divs. The processing model applies the necessary
CSS styles to the cue divs to prepare them for display on the web page. During this process the cue divs get added
to a block level element (overlay). The overlay should be a part of the live DOM as the algorithm will use the
computed styles (only of the divs to do overlap avoidance.

You can pass an optional options object as an argument to override the default styles. See the code for what styles
are supported.

```javascript
var divs = WebVTT.processCues(window, cues, overlay);
var divs = WebVTT.processCues(window, cues, overlay, options);
```

## ParsingError
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38 changes: 28 additions & 10 deletions lib/vtt.js
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Original file line number Diff line number Diff line change
Expand Up @@ -545,8 +545,8 @@ function CueStyleBox(window, cue, styleOptions) {
// have inline positioning and will function as the cue background box.
this.cueDiv = parseContent(window, cue.text);
var styles = {
color: "rgba(255, 255, 255, 1)",
backgroundColor: "rgba(0, 0, 0, 0.8)",
color: styleOptions.color || "inherit",
backgroundColor: styleOptions.backgroundColor || "inherit",
position: "relative",
left: 0,
right: 0,
Expand All @@ -572,7 +572,10 @@ function CueStyleBox(window, cue, styleOptions) {
: "vertical-rl",
unicodeBidi: "plaintext",
textAlign: cue.align === "middle" ? "center" : cue.align,
font: styleOptions.font,
font: styleOptions.font || "inherit",
fontVariant: styleOptions.fontVariant || "inherit",
textShadow: styleOptions.textShadow || "inherit",
backgroundColor: styleOptions.windowColor || "inherit",
whiteSpace: "pre-line",
position: "absolute"
};
Expand Down Expand Up @@ -930,18 +933,23 @@ WebVTT.convertCueToDOMTree = function(window, cuetext) {
return parseContent(window, cuetext);
};

var FONT_SIZE_PERCENT = 0.05;
var FONT_STYLE = "sans-serif";
var CUE_BACKGROUND_PADDING = "1.5%";
var DEFAULT_FONT_SIZE_PERCENT = 5; // 5% of the height of the video window
var DEFAULT_FONT_STYLE = "sans-serif";
var DEFAULT_CUE_BACKGROUND_PADDING = "1.5%";
var DEFAULT_FOREGROUND_COLOR = "rgba(255, 255, 255, 1)"; // White, 100% opaque
var DEFAULT_BACKGROUND_COLOR = "rgba(0, 0, 0, 0.8)"; // Black, 80% opaque
var DEFAULT_WINDOW_COLOR = "rgba(0, 0, 0, 0.0)"; // Black, translucent

// Runs the processing model over the cues and regions passed to it.
// @param overlay A block level element (usually a div) that the computed cues
// and regions will be placed into.
WebVTT.processCues = function(window, cues, overlay) {
WebVTT.processCues = function(window, cues, overlay, styles) {
if (!window || !cues || !overlay) {
return null;
}

styles = styles || {};

// Remove all previous children.
while (overlay.firstChild) {
overlay.removeChild(overlay.firstChild);
Expand All @@ -953,7 +961,7 @@ WebVTT.processCues = function(window, cues, overlay) {
paddedOverlay.style.right = "0";
paddedOverlay.style.top = "0";
paddedOverlay.style.bottom = "0";
paddedOverlay.style.margin = CUE_BACKGROUND_PADDING;
paddedOverlay.style.margin = styles.cueBackgroundMargin || DEFAULT_CUE_BACKGROUND_PADDING;
overlay.appendChild(paddedOverlay);

// Determine if we need to compute the display states of the cues. This could
Expand All @@ -978,11 +986,21 @@ WebVTT.processCues = function(window, cues, overlay) {

var boxPositions = [],
containerBox = BoxPosition.getSimpleBoxPosition(paddedOverlay),
fontSize = Math.round(containerBox.height * FONT_SIZE_PERCENT * 100) / 100;
fontSize = Math.round(containerBox.height * ((styles.fontSizePercent || 100.0) / 100.0) * DEFAULT_FONT_SIZE_PERCENT) / 100;
var styleOptions = {
font: fontSize + "px " + FONT_STYLE
color: styles.color || DEFAULT_FOREGROUND_COLOR,
backgroundColor: styles.backgroundColor || DEFAULT_BACKGROUND_COLOR,
windowColor: styles.windowColor || DEFAULT_WINDOW_COLOR,
font: fontSize + "px " + (styles.fontStyle || DEFAULT_FONT_STYLE)
};

if (styles.fontVariant) {
styleOptions.fontVariant = styles.fontVariant;
}
if (styles.textShadow) {
styleOptions.textShadow = styles.textShadow;
}

(function() {
var styleBox, cue;

Expand Down