
This requires an implementation of the "text preparation algorithm" as specified here: html.spec.whatwg.org/multipage/canvas.html#text-preparation-algorithm However, we're missing a lot of things such as the CanvasTextDrawingStyles interface, so most of the algorithm was not implemented. Additionally, we also are not able to use a LineBox like the algorithm suggests, because our layouting infra is not up to the task yet. The prepare_text function does nothing other than figuring out the width of the given text and return glyphs with offsets at the moment.
17 lines
658 B
Text
17 lines
658 B
Text
interface TextMetrics {
|
|
// x-direction
|
|
readonly attribute double width; // advance width
|
|
readonly attribute double actualBoundingBoxLeft;
|
|
readonly attribute double actualBoundingBoxRight;
|
|
|
|
// y-direction
|
|
readonly attribute double fontBoundingBoxAscent;
|
|
readonly attribute double fontBoundingBoxDescent;
|
|
readonly attribute double actualBoundingBoxAscent;
|
|
readonly attribute double actualBoundingBoxDescent;
|
|
readonly attribute double emHeightAscent;
|
|
readonly attribute double emHeightDescent;
|
|
readonly attribute double hangingBaseline;
|
|
readonly attribute double alphabeticBaseline;
|
|
readonly attribute double ideographicBaseline;
|
|
};
|