void RenderTextTrackCue::repositionCueSnapToLinesSet()
{
InlineFlowBox* firstLineBox;
LayoutUnit step;
LayoutUnit position;
if (!initializeLayoutParameters(firstLineBox, step, position))
return;
bool switched;
placeBoxInDefaultPosition(position, switched);
// 11. Step loop: If none of the boxes in boxes would overlap any of the boxes
// in output and all the boxes in output are within the video's rendering area
// then jump to the step labeled done positioning.
while (isOutside() || isOverlapping()) {
if (!shouldSwitchDirection(firstLineBox, step))
// 13. Move all the boxes in boxes ...
// 14. Jump back to the step labeled step loop.
moveBoxesByStep(step);
else if (!switchDirection(switched, step))
break;
// 19. Jump back to the step labeled step loop.
}
// Acommodate extra top and bottom padding, border or margin.
// Note: this is supported only for internal UA styling, not through the cue selector.
if (hasInlineDirectionBordersPaddingOrMargin())
moveIfNecessaryToKeepWithinContainer();
}
void RenderVTTCue::repositionCueSnapToLinesSet()
{
InlineFlowBox* firstLineBox;
LayoutUnit step;
LayoutUnit position;
if (!findFirstLineBox(firstLineBox))
return;
if (!initializeLayoutParameters(firstLineBox, step, position))
return;
bool switched;
placeBoxInDefaultPosition(position, switched);
// 11. Step loop: If none of the boxes in boxes would overlap any of the boxes
// in output and all the boxes in output are within the video's rendering area
// then jump to the step labeled done positioning.
while (isOutside() || isOverlapping()) {
if (!shouldSwitchDirection(firstLineBox, step)) {
// 13. Move all the boxes in boxes ...
// 14. Jump back to the step labeled step loop.
moveBoxesByStep(step);
} else if (!switchDirection(switched, step)) {
break;
}
// 19. Jump back to the step labeled step loop.
}
// Acommodate extra top and bottom padding, border or margin.
// Note: this is supported only for internal UA styling, not through the cue selector.
if (hasInlineDirectionBordersPaddingOrMargin()) {
IntRect containerRect = containingBlock()->absoluteBoundingBoxRect();
IntRect cueRect = absoluteBoundingBoxRect();
int topOverflow = cueRect.y() - containerRect.y();
int bottomOverflow = containerRect.y() + containerRect.height() - cueRect.y() - cueRect.height();
int adjustment = 0;
if (topOverflow < 0)
adjustment = -topOverflow;
else if (bottomOverflow < 0)
adjustment = bottomOverflow;
if (adjustment)
setY(y() + adjustment);
}
}
void SnapToLinesLayouter::layout()
{
// http://dev.w3.org/html5/webvtt/#dfn-apply-webvtt-cue-settings
// Step 13, "If cue's text track cue snap-to-lines flag is set".
InlineFlowBox* firstLineBox = findFirstLineBox();
if (!firstLineBox)
return;
// Steps 1-3 skipped.
// 4. Horizontal: Let step be the height of the first line box in boxes.
// Vertical: Let step be the width of the first line box in boxes.
LayoutUnit step = firstLineBox->logicalHeight();
// 5. If step is zero, then jump to the step labeled done positioning below.
if (!step)
return;
// Steps 6-11.
LayoutUnit positionAdjustment = computeInitialPositionAdjustment(step);
// 12. Move all boxes in boxes ...
// Horizontal: ... down by the distance given by position
// Vertical: ... right by the distance given by position
moveBoxesBy(positionAdjustment);
// 13. Remember the position of all the boxes in boxes as their specified
// position.
m_specifiedPosition = m_cueBox.location();
// 14. Let best position be null. It will hold a position for boxes, much
// like specified position in the previous step.
// 15. Let best position score be null.
// 16. Let switched be false.
bool switched = false;
// Step 17 skipped. (margin == 0; title area == video area)
// 18. Step loop: If none of the boxes in boxes would overlap any of the
// boxes in output, and all of the boxes in output are entirely within the
// title area box, then jump to the step labeled done positioning below.
while (isOutside() || isOverlapping()) {
// 19. Let current position score be the percentage of the area of the
// bounding box of the boxes in boxes that is outside the title area
// box.
// 20. If best position is null (i.e. this is the first run through
// this loop, switched is still false, the boxes in boxes are at their
// specified position, and best position score is still null), or if
// current position score is a lower percentage than that in best
// position score, then remember the position of all the boxes in boxes
// as their best position, and set best position score to current
// position score.
if (!shouldSwitchDirection(firstLineBox, step)) {
// 22. Horizontal: Move all the boxes in boxes down by the distance
// given by step. (If step is negative, then this will actually
// result in an upwards movement of the boxes in absolute terms.)
// Vertical: Move all the boxes in boxes right by the distance
// given by step. (If step is negative, then this will actually
// result in a leftwards movement of the boxes in absolute terms.)
moveBoxesBy(step);
// 23. Jump back to the step labeled step loop.
continue;
}
// 24. Switch direction: If switched is true, then move all the boxes in
// boxes back to their best position, and jump to the step labeled done
// positioning below.
// 25. Otherwise, move all the boxes in boxes back to their specified
// position as determined in the earlier step.
m_cueBox.setLocation(m_specifiedPosition);
// XX. If switched is true, jump to the step labeled done
// positioning below.
if (switched)
break;
// 26. Negate step.
step = -step;
// 27. Set switched to true.
switched = true;
// 28. Jump back to the step labeled step loop.
}
}
