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/*
* Copyright (C) 2013 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "web/PageScaleConstraintsSet.h"
#include "platform/Length.h"
#include "wtf/Assertions.h"
using namespace WebCore;
namespace blink {
static const float defaultMinimumScale = 0.25f;
static const float defaultMaximumScale = 5.0f;
PageScaleConstraintsSet::PageScaleConstraintsSet()
: m_lastContentsWidth(0)
, m_needsReset(false)
, m_constraintsDirty(false)
{
m_finalConstraints = defaultConstraints();
}
PageScaleConstraints PageScaleConstraintsSet::defaultConstraints() const
{
return PageScaleConstraints(-1, defaultMinimumScale, defaultMaximumScale);
}
void PageScaleConstraintsSet::updatePageDefinedConstraints(const ViewportDescription& description, Length legacyFallbackWidth)
{
m_pageDefinedConstraints = description.resolve(m_viewSize, legacyFallbackWidth);
m_constraintsDirty = true;
}
void PageScaleConstraintsSet::setUserAgentConstraints(const PageScaleConstraints& userAgentConstraints)
{
m_userAgentConstraints = userAgentConstraints;
m_constraintsDirty = true;
}
PageScaleConstraints PageScaleConstraintsSet::computeConstraintsStack() const
{
PageScaleConstraints constraints = defaultConstraints();
constraints.overrideWith(m_pageDefinedConstraints);
constraints.overrideWith(m_userAgentConstraints);
return constraints;
}
void PageScaleConstraintsSet::computeFinalConstraints()
{
m_finalConstraints = computeConstraintsStack();
m_constraintsDirty = false;
}
void PageScaleConstraintsSet::adjustFinalConstraintsToContentsSize(IntSize contentsSize, int nonOverlayScrollbarWidth)
{
m_finalConstraints.fitToContentsWidth(contentsSize.width(), m_viewSize.width() - nonOverlayScrollbarWidth);
}
void PageScaleConstraintsSet::setNeedsReset(bool needsReset)
{
m_needsReset = needsReset;
if (needsReset)
m_constraintsDirty = true;
}
void PageScaleConstraintsSet::didChangeContentsSize(IntSize contentsSize, float pageScaleFactor)
{
// If a large fixed-width element expanded the size of the document late in
// loading and our initial scale is not set (or set to be less than the last
// minimum scale), reset the page scale factor to the new initial scale.
if (contentsSize.width() > m_lastContentsWidth
&& pageScaleFactor == finalConstraints().minimumScale
&& computeConstraintsStack().initialScale < finalConstraints().minimumScale)
setNeedsReset(true);
m_constraintsDirty = true;
m_lastContentsWidth = contentsSize.width();
}
static float computeDeprecatedTargetDensityDPIFactor(const ViewportDescription& description, float deviceScaleFactor)
{
if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueDeviceDPI)
return 1.0f / deviceScaleFactor;
float targetDPI = -1.0f;
if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueLowDPI)
targetDPI = 120.0f;
else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueMediumDPI)
targetDPI = 160.0f;
else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueHighDPI)
targetDPI = 240.0f;
else if (description.deprecatedTargetDensityDPI != ViewportDescription::ValueAuto)
targetDPI = description.deprecatedTargetDensityDPI;
return targetDPI > 0 ? 160.0f / targetDPI : 1.0f;
}
static float getLayoutWidthForNonWideViewport(const FloatSize& deviceSize, float initialScale)
{
return initialScale == -1 ? deviceSize.width() : deviceSize.width() / initialScale;
}
static float computeHeightByAspectRatio(float width, const FloatSize& deviceSize)
{
return width * (deviceSize.height() / deviceSize.width());
}
void PageScaleConstraintsSet::didChangeViewSize(const IntSize& size)
{
if (m_viewSize == size)
return;
m_viewSize = size;
m_constraintsDirty = true;
}
IntSize PageScaleConstraintsSet::mainFrameSize(const IntSize& contentsSize) const
{
// If there's no explicit minimum scale factor set, size the frame so that its width == content width
// so there's no horizontal scrolling at the minimum scale.
if (m_pageDefinedConstraints.minimumScale < finalConstraints().minimumScale
&& m_userAgentConstraints.minimumScale < finalConstraints().minimumScale
&& contentsSize.width()
&& m_viewSize.width())
return IntSize(contentsSize.width(), computeHeightByAspectRatio(contentsSize.width(), m_viewSize));
// If there is a minimum scale (or there's no content size yet), the frame size should match the viewport
// size at minimum scale, since the viewport must always be contained by the frame.
IntSize frameSize(m_viewSize);
frameSize.scale(1 / finalConstraints().minimumScale);
return frameSize;
}
void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode, bool nonUserScalableQuirkEnabled)
{
if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode && !nonUserScalableQuirkEnabled)
return;
const float oldInitialScale = m_pageDefinedConstraints.initialScale;
if (!loadWithOverviewMode) {
bool resetInitialScale = false;
if (description.zoom == -1) {
if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom)
resetInitialScale = true;
if (useWideViewport || description.maxWidth.type() == DeviceWidth)
resetInitialScale = true;
}
if (resetInitialScale)
m_pageDefinedConstraints.initialScale = 1.0f;
}
float adjustedLayoutSizeWidth = m_pageDefinedConstraints.layoutSize.width();
float adjustedLayoutSizeHeight = m_pageDefinedConstraints.layoutSize.height();
float targetDensityDPIFactor = 1.0f;
if (supportTargetDensityDPI) {
targetDensityDPIFactor = computeDeprecatedTargetDensityDPIFactor(description, deviceScaleFactor);
if (m_pageDefinedConstraints.initialScale != -1)
m_pageDefinedConstraints.initialScale *= targetDensityDPIFactor;
if (m_pageDefinedConstraints.minimumScale != -1)
m_pageDefinedConstraints.minimumScale *= targetDensityDPIFactor;
if (m_pageDefinedConstraints.maximumScale != -1)
m_pageDefinedConstraints.maximumScale *= targetDensityDPIFactor;
if (wideViewportQuirkEnabled && (!useWideViewport || description.maxWidth.type() == DeviceWidth)) {
adjustedLayoutSizeWidth /= targetDensityDPIFactor;
adjustedLayoutSizeHeight /= targetDensityDPIFactor;
}
}
if (wideViewportQuirkEnabled) {
if (useWideViewport && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom != 1.0f) {
adjustedLayoutSizeWidth = layoutFallbackWidth;
adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
} else if (!useWideViewport) {
const float nonWideScale = description.zoom < 1 && description.maxWidth.type() != DeviceWidth && description.maxWidth.type() != DeviceHeight ? -1 : oldInitialScale;
adjustedLayoutSizeWidth = getLayoutWidthForNonWideViewport(m_viewSize, nonWideScale) / targetDensityDPIFactor;
float newInitialScale = targetDensityDPIFactor;
if (m_userAgentConstraints.initialScale != -1 && (description.maxWidth.type() == DeviceWidth || ((description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom == -1))) {
adjustedLayoutSizeWidth /= m_userAgentConstraints.initialScale;
newInitialScale = m_userAgentConstraints.initialScale;
}
adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
if (description.zoom < 1) {
m_pageDefinedConstraints.initialScale = newInitialScale;
if (m_pageDefinedConstraints.minimumScale != -1)
m_pageDefinedConstraints.minimumScale = std::min<float>(m_pageDefinedConstraints.minimumScale, m_pageDefinedConstraints.initialScale);
if (m_pageDefinedConstraints.maximumScale != -1)
m_pageDefinedConstraints.maximumScale = std::max<float>(m_pageDefinedConstraints.maximumScale, m_pageDefinedConstraints.initialScale);
}
}
}
if (nonUserScalableQuirkEnabled && !description.userZoom) {
m_pageDefinedConstraints.initialScale = targetDensityDPIFactor;
m_pageDefinedConstraints.minimumScale = m_pageDefinedConstraints.initialScale;
m_pageDefinedConstraints.maximumScale = m_pageDefinedConstraints.initialScale;
if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom || description.maxWidth.type() == DeviceWidth) {
adjustedLayoutSizeWidth = m_viewSize.width() / targetDensityDPIFactor;
adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
}
}
m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
}
} // namespace WebCore
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