PageScaleConstraints ViewportDescription::resolve(const FloatSize& initialViewportSize, Length legacyFallbackWidth) const
{
float resultWidth = ValueAuto;
Length copyMaxWidth = maxWidth;
Length copyMinWidth = minWidth;
// In case the width (used for min- and max-width) is undefined.
if (isLegacyViewportType() && maxWidth.isAuto()) {
// The width viewport META property is translated into 'width' descriptors, setting
// the 'min' value to 'extend-to-zoom' and the 'max' value to the intended length.
// In case the UA-defines a min-width, use that as length.
if (zoom == ViewportDescription::ValueAuto) {
copyMinWidth = Length(ExtendToZoom);
copyMaxWidth = legacyFallbackWidth;
} else if (maxHeight.isAuto()) {
copyMinWidth = Length(ExtendToZoom);
copyMaxWidth = Length(ExtendToZoom);
}
}
float resultMaxWidth = resolveViewportLength(copyMaxWidth, initialViewportSize, Horizontal);
float resultMinWidth = resolveViewportLength(copyMinWidth, initialViewportSize, Horizontal);
float resultHeight = ValueAuto;
float resultMaxHeight = resolveViewportLength(maxHeight, initialViewportSize, Vertical);
float resultMinHeight = resolveViewportLength(minHeight, initialViewportSize, Vertical);
float resultZoom = zoom;
float resultMinZoom = minZoom;
float resultMaxZoom = maxZoom;
float resultUserZoom = userZoom;
// 1. Resolve min-zoom and max-zoom values.
if (resultMinZoom != ViewportDescription::ValueAuto && resultMaxZoom != ViewportDescription::ValueAuto)
resultMaxZoom = max(resultMinZoom, resultMaxZoom);
// 2. Constrain zoom value to the [min-zoom, max-zoom] range.
if (resultZoom != ViewportDescription::ValueAuto)
resultZoom = compareIgnoringAuto(resultMinZoom, compareIgnoringAuto(resultMaxZoom, resultZoom, min), max);
float extendZoom = compareIgnoringAuto(resultZoom, resultMaxZoom, min);
// 3. Resolve non-"auto" lengths to pixel lengths.
if (extendZoom == ViewportDescription::ValueAuto) {
if (resultMaxWidth == ViewportDescription::ValueExtendToZoom)
resultMaxWidth = ViewportDescription::ValueAuto;
if (resultMaxHeight == ViewportDescription::ValueExtendToZoom)
resultMaxHeight = ViewportDescription::ValueAuto;
if (resultMinWidth == ViewportDescription::ValueExtendToZoom)
resultMinWidth = resultMaxWidth;
if (resultMinHeight == ViewportDescription::ValueExtendToZoom)
resultMinHeight = resultMaxHeight;
} else {
float extendWidth = initialViewportSize.width() / extendZoom;
float extendHeight = initialViewportSize.height() / extendZoom;
if (resultMaxWidth == ViewportDescription::ValueExtendToZoom)
resultMaxWidth = extendWidth;
if (resultMaxHeight == ViewportDescription::ValueExtendToZoom)
resultMaxHeight = extendHeight;
if (resultMinWidth == ViewportDescription::ValueExtendToZoom)
resultMinWidth = compareIgnoringAuto(extendWidth, resultMaxWidth, max);
if (resultMinHeight == ViewportDescription::ValueExtendToZoom)
resultMinHeight = compareIgnoringAuto(extendHeight, resultMaxHeight, max);
}
// 4. Resolve initial width from min/max descriptors.
if (resultMinWidth != ViewportDescription::ValueAuto || resultMaxWidth != ViewportDescription::ValueAuto)
resultWidth = compareIgnoringAuto(resultMinWidth, compareIgnoringAuto(resultMaxWidth, initialViewportSize.width(), min), max);
// 5. Resolve initial height from min/max descriptors.
if (resultMinHeight != ViewportDescription::ValueAuto || resultMaxHeight != ViewportDescription::ValueAuto)
resultHeight = compareIgnoringAuto(resultMinHeight, compareIgnoringAuto(resultMaxHeight, initialViewportSize.height(), min), max);
// 6-7. Resolve width value.
if (resultWidth == ViewportDescription::ValueAuto) {
if (resultHeight == ViewportDescription::ValueAuto || !initialViewportSize.height())
resultWidth = initialViewportSize.width();
else
resultWidth = resultHeight * (initialViewportSize.width() / initialViewportSize.height());
}
// 8. Resolve height value.
if (resultHeight == ViewportDescription::ValueAuto) {
if (!initialViewportSize.width())
resultHeight = initialViewportSize.height();
else
resultHeight = resultWidth * initialViewportSize.height() / initialViewportSize.width();
}
// Resolve initial-scale value.
if (resultZoom == ViewportDescription::ValueAuto) {
if (resultWidth != ViewportDescription::ValueAuto && resultWidth > 0)
resultZoom = initialViewportSize.width() / resultWidth;
if (resultHeight != ViewportDescription::ValueAuto && resultHeight > 0) {
// if 'auto', the initial-scale will be negative here and thus ignored.
resultZoom = max<float>(resultZoom, initialViewportSize.height() / resultHeight);
}
}
// If user-scalable = no, lock the min/max scale to the computed initial
// scale.
if (!resultUserZoom)
resultMinZoom = resultMaxZoom = resultZoom;
// Only set initialScale to a value if it was explicitly set.
if (zoom == ViewportDescription::ValueAuto)
resultZoom = ViewportDescription::ValueAuto;
PageScaleConstraints result;
result.minimumScale = resultMinZoom;
result.maximumScale = resultMaxZoom;
result.initialScale = resultZoom;
result.layoutSize.setWidth(resultWidth);
result.layoutSize.setHeight(resultHeight);
return result;
}
ViewportAttributes ViewportArguments::resolve(const FloatSize& initialViewportSize, const FloatSize& deviceSize, int defaultWidth) const
{
float resultWidth = width;
float resultMaxWidth = maxWidth;
float resultMinWidth = minWidth;
float resultHeight = height;
float resultMinHeight = minHeight;
float resultMaxHeight = maxHeight;
float resultZoom = zoom;
float resultMinZoom = minZoom;
float resultMaxZoom = maxZoom;
float resultUserZoom = userZoom;
switch (int(resultWidth)) {
case ViewportArguments::ValueDeviceWidth:
resultWidth = deviceSize.width();
break;
case ViewportArguments::ValueDeviceHeight:
resultWidth = deviceSize.height();
break;
}
switch (int(resultHeight)) {
case ViewportArguments::ValueDeviceWidth:
resultHeight = deviceSize.width();
break;
case ViewportArguments::ValueDeviceHeight:
resultHeight = deviceSize.height();
break;
}
if (type == ViewportArguments::CSSDeviceAdaptation) {
switch (int(resultMinWidth)) {
case ViewportArguments::ValueDeviceWidth:
resultMinWidth = deviceSize.width();
break;
case ViewportArguments::ValueDeviceHeight:
resultMinWidth = deviceSize.height();
break;
}
switch (int(resultMaxWidth)) {
case ViewportArguments::ValueDeviceWidth:
resultMaxWidth = deviceSize.width();
break;
case ViewportArguments::ValueDeviceHeight:
resultMaxWidth = deviceSize.height();
break;
}
switch (int(resultMinHeight)) {
case ViewportArguments::ValueDeviceWidth:
resultMinHeight = deviceSize.width();
break;
case ViewportArguments::ValueDeviceHeight:
resultMinHeight = deviceSize.height();
break;
}
switch (int(resultMaxHeight)) {
case ViewportArguments::ValueDeviceWidth:
resultMaxHeight = deviceSize.width();
break;
case ViewportArguments::ValueDeviceHeight:
resultMaxHeight = deviceSize.height();
break;
}
if (resultMinWidth != ViewportArguments::ValueAuto || resultMaxWidth != ViewportArguments::ValueAuto)
resultWidth = compareIgnoringAuto(resultMinWidth, compareIgnoringAuto(resultMaxWidth, deviceSize.width(), min), max);
if (resultMinHeight != ViewportArguments::ValueAuto || resultMaxHeight != ViewportArguments::ValueAuto)
resultHeight = compareIgnoringAuto(resultMinHeight, compareIgnoringAuto(resultMaxHeight, deviceSize.height(), min), max);
if (resultMinZoom != ViewportArguments::ValueAuto && resultMaxZoom != ViewportArguments::ValueAuto)
resultMaxZoom = max(resultMinZoom, resultMaxZoom);
if (resultZoom != ViewportArguments::ValueAuto)
resultZoom = compareIgnoringAuto(resultMinZoom, compareIgnoringAuto(resultMaxZoom, resultZoom, min), max);
if (resultWidth == ViewportArguments::ValueAuto && resultZoom == ViewportArguments::ValueAuto)
resultWidth = deviceSize.width();
if (resultWidth == ViewportArguments::ValueAuto && resultHeight == ViewportArguments::ValueAuto)
resultWidth = deviceSize.width() / resultZoom;
if (resultWidth == ViewportArguments::ValueAuto)
resultWidth = resultHeight * deviceSize.width() / deviceSize.height();
if (resultHeight == ViewportArguments::ValueAuto)
resultHeight = resultWidth * deviceSize.height() / deviceSize.width();
if (resultZoom != ViewportArguments::ValueAuto || resultMaxZoom != ViewportArguments::ValueAuto) {
resultWidth = compareIgnoringAuto(resultWidth, deviceSize.width() / compareIgnoringAuto(resultZoom, resultMaxZoom, min), max);
resultHeight = compareIgnoringAuto(resultHeight, deviceSize.height() / compareIgnoringAuto(resultZoom, resultMaxZoom, min), max);
}
}
// Clamp values to valid range.
resultWidth = clampLengthValue(resultWidth);
resultHeight = clampLengthValue(resultHeight);
resultZoom = clampScaleValue(resultZoom);
resultMinZoom = clampScaleValue(resultMinZoom);
resultMaxZoom = clampScaleValue(resultMaxZoom);
ViewportAttributes result;
result.orientation = orientation;
// Resolve minimum-scale and maximum-scale values according to spec.
if (resultMinZoom == ViewportArguments::ValueAuto)
result.minimumScale = float(0.25);
else
result.minimumScale = resultMinZoom;
if (resultMaxZoom == ViewportArguments::ValueAuto) {
result.maximumScale = float(5.0);
result.minimumScale = min(float(5.0), result.minimumScale);
} else
result.maximumScale = resultMaxZoom;
result.maximumScale = max(result.minimumScale, result.maximumScale);
// Resolve initial-scale value.
result.initialScale = resultZoom;
if (resultZoom == ViewportArguments::ValueAuto) {
result.initialScale = initialViewportSize.width() / defaultWidth;
if (resultWidth != ViewportArguments::ValueAuto)
result.initialScale = initialViewportSize.width() / resultWidth;
if (resultHeight != ViewportArguments::ValueAuto) {
// if 'auto', the initial-scale will be negative here and thus ignored.
result.initialScale = max<float>(result.initialScale, initialViewportSize.height() / resultHeight);
}
}
// Constrain initial-scale value to minimum-scale/maximum-scale range.
result.initialScale = min(result.maximumScale, max(result.minimumScale, result.initialScale));
// Resolve width value.
if (resultWidth == ViewportArguments::ValueAuto) {
if (resultZoom == ViewportArguments::ValueAuto)
resultWidth = defaultWidth;
else if (resultHeight != ViewportArguments::ValueAuto)
resultWidth = resultHeight * (initialViewportSize.width() / initialViewportSize.height());
else
resultWidth = initialViewportSize.width() / result.initialScale;
}
// Resolve height value.
if (resultHeight == ViewportArguments::ValueAuto)
resultHeight = resultWidth * (initialViewportSize.height() / initialViewportSize.width());
// Extend width and height to fill the visual viewport for the resolved initial-scale.
resultWidth = max<float>(resultWidth, initialViewportSize.width() / result.initialScale);
resultHeight = max<float>(resultHeight, initialViewportSize.height() / result.initialScale);
result.layoutSize.setWidth(resultWidth);
result.layoutSize.setHeight(resultHeight);
// FIXME: This might affect some ports, but is the right thing to do.
// Only set initialScale to a value if it was explicitly set.
// if (resultZoom == ViewportArguments::ValueAuto)
// result.initialScale = ViewportArguments::ValueAuto;
result.userScalable = resultUserZoom;
result.orientation = orientation;
return result;
}
