1 /*
2 * Copyright (C) 2013 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "config.h"
32 #include "PageScaleConstraintsSet.h"
33
34 #include "wtf/Assertions.h"
35
36 using namespace WebCore;
37
38 namespace blink {
39
40 static const float defaultMinimumScale = 0.25f;
41 static const float defaultMaximumScale = 5.0f;
42
PageScaleConstraintsSet()43 PageScaleConstraintsSet::PageScaleConstraintsSet()
44 : m_lastContentsWidth(0)
45 , m_needsReset(false)
46 , m_constraintsDirty(false)
47 {
48 m_finalConstraints = defaultConstraints();
49 }
50
defaultConstraints() const51 PageScaleConstraints PageScaleConstraintsSet::defaultConstraints() const
52 {
53 return PageScaleConstraints(-1, defaultMinimumScale, defaultMaximumScale);
54 }
55
updatePageDefinedConstraints(const ViewportDescription & description,IntSize viewSize)56 void PageScaleConstraintsSet::updatePageDefinedConstraints(const ViewportDescription& description, IntSize viewSize)
57 {
58 m_pageDefinedConstraints = description.resolve(viewSize);
59
60 m_constraintsDirty = true;
61 }
62
setUserAgentConstraints(const PageScaleConstraints & userAgentConstraints)63 void PageScaleConstraintsSet::setUserAgentConstraints(const PageScaleConstraints& userAgentConstraints)
64 {
65 m_userAgentConstraints = userAgentConstraints;
66 m_constraintsDirty = true;
67 }
68
computeConstraintsStack() const69 PageScaleConstraints PageScaleConstraintsSet::computeConstraintsStack() const
70 {
71 PageScaleConstraints constraints = defaultConstraints();
72 constraints.overrideWith(m_pageDefinedConstraints);
73 constraints.overrideWith(m_userAgentConstraints);
74 return constraints;
75 }
76
computeFinalConstraints()77 void PageScaleConstraintsSet::computeFinalConstraints()
78 {
79 m_finalConstraints = computeConstraintsStack();
80
81 m_constraintsDirty = false;
82 }
83
adjustFinalConstraintsToContentsSize(IntSize viewSize,IntSize contentsSize,int nonOverlayScrollbarWidth)84 void PageScaleConstraintsSet::adjustFinalConstraintsToContentsSize(IntSize viewSize, IntSize contentsSize, int nonOverlayScrollbarWidth)
85 {
86 m_finalConstraints.fitToContentsWidth(contentsSize.width(), viewSize.width() - nonOverlayScrollbarWidth);
87 }
88
setNeedsReset(bool needsReset)89 void PageScaleConstraintsSet::setNeedsReset(bool needsReset)
90 {
91 m_needsReset = needsReset;
92 if (needsReset)
93 m_constraintsDirty = true;
94 }
95
didChangeContentsSize(IntSize contentsSize,float pageScaleFactor)96 void PageScaleConstraintsSet::didChangeContentsSize(IntSize contentsSize, float pageScaleFactor)
97 {
98 // If a large fixed-width element expanded the size of the document late in
99 // loading and our initial scale is not set (or set to be less than the last
100 // minimum scale), reset the page scale factor to the new initial scale.
101 if (contentsSize.width() > m_lastContentsWidth
102 && pageScaleFactor == finalConstraints().minimumScale
103 && computeConstraintsStack().initialScale < finalConstraints().minimumScale)
104 setNeedsReset(true);
105
106 m_constraintsDirty = true;
107 m_lastContentsWidth = contentsSize.width();
108 }
109
computeDeprecatedTargetDensityDPIFactor(const ViewportDescription & description,float deviceScaleFactor)110 static float computeDeprecatedTargetDensityDPIFactor(const ViewportDescription& description, float deviceScaleFactor)
111 {
112 if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueDeviceDPI)
113 return 1.0f / deviceScaleFactor;
114
115 float targetDPI = -1.0f;
116 if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueLowDPI)
117 targetDPI = 120.0f;
118 else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueMediumDPI)
119 targetDPI = 160.0f;
120 else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueHighDPI)
121 targetDPI = 240.0f;
122 else if (description.deprecatedTargetDensityDPI != ViewportDescription::ValueAuto)
123 targetDPI = description.deprecatedTargetDensityDPI;
124 return targetDPI > 0 ? 160.0f / targetDPI : 1.0f;
125 }
126
getLayoutWidthForNonWideViewport(const FloatSize & deviceSize,float initialScale)127 static float getLayoutWidthForNonWideViewport(const FloatSize& deviceSize, float initialScale)
128 {
129 return initialScale == -1 ? deviceSize.width() : deviceSize.width() / initialScale;
130 }
131
computeHeightByAspectRatio(float width,const FloatSize & deviceSize)132 static float computeHeightByAspectRatio(float width, const FloatSize& deviceSize)
133 {
134 return width * (deviceSize.height() / deviceSize.width());
135 }
136
adjustForAndroidWebViewQuirks(const ViewportDescription & description,IntSize viewSize,int layoutFallbackWidth,float deviceScaleFactor,bool supportTargetDensityDPI,bool wideViewportQuirkEnabled,bool useWideViewport,bool loadWithOverviewMode,bool nonUserScalableQuirkEnabled)137 void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, IntSize viewSize, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode, bool nonUserScalableQuirkEnabled)
138 {
139 if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode && !nonUserScalableQuirkEnabled)
140 return;
141
142 const float oldInitialScale = m_pageDefinedConstraints.initialScale;
143 if (!loadWithOverviewMode) {
144 bool resetInitialScale = false;
145 if (description.zoom == -1) {
146 if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom)
147 resetInitialScale = true;
148 if (useWideViewport || description.maxWidth == Length(100, ViewportPercentageWidth))
149 resetInitialScale = true;
150 }
151 if (resetInitialScale)
152 m_pageDefinedConstraints.initialScale = 1.0f;
153 }
154
155 float adjustedLayoutSizeWidth = m_pageDefinedConstraints.layoutSize.width();
156 float adjustedLayoutSizeHeight = m_pageDefinedConstraints.layoutSize.height();
157 float targetDensityDPIFactor = 1.0f;
158
159 if (supportTargetDensityDPI) {
160 targetDensityDPIFactor = computeDeprecatedTargetDensityDPIFactor(description, deviceScaleFactor);
161 if (m_pageDefinedConstraints.initialScale != -1)
162 m_pageDefinedConstraints.initialScale *= targetDensityDPIFactor;
163 if (m_pageDefinedConstraints.minimumScale != -1)
164 m_pageDefinedConstraints.minimumScale *= targetDensityDPIFactor;
165 if (m_pageDefinedConstraints.maximumScale != -1)
166 m_pageDefinedConstraints.maximumScale *= targetDensityDPIFactor;
167 if (wideViewportQuirkEnabled && (!useWideViewport || description.maxWidth == Length(100, ViewportPercentageWidth))) {
168 adjustedLayoutSizeWidth /= targetDensityDPIFactor;
169 adjustedLayoutSizeHeight /= targetDensityDPIFactor;
170 }
171 }
172
173 if (wideViewportQuirkEnabled) {
174 if (useWideViewport && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom != 1.0f) {
175 adjustedLayoutSizeWidth = layoutFallbackWidth;
176 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, viewSize);
177 } else if (!useWideViewport) {
178 const float nonWideScale = description.zoom < 1 && !description.maxWidth.isViewportPercentage() ? -1 : oldInitialScale;
179 adjustedLayoutSizeWidth = getLayoutWidthForNonWideViewport(viewSize, nonWideScale) / targetDensityDPIFactor;
180 float newInitialScale = targetDensityDPIFactor;
181 if (m_userAgentConstraints.initialScale != -1 && (description.maxWidth == Length(100, ViewportPercentageWidth) || ((description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom == -1))) {
182 adjustedLayoutSizeWidth /= m_userAgentConstraints.initialScale;
183 newInitialScale = m_userAgentConstraints.initialScale;
184 }
185 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, viewSize);
186 if (description.zoom < 1) {
187 m_pageDefinedConstraints.initialScale = newInitialScale;
188 if (m_pageDefinedConstraints.minimumScale != -1)
189 m_pageDefinedConstraints.minimumScale = std::min<float>(m_pageDefinedConstraints.minimumScale, m_pageDefinedConstraints.initialScale);
190 if (m_pageDefinedConstraints.maximumScale != -1)
191 m_pageDefinedConstraints.maximumScale = std::max<float>(m_pageDefinedConstraints.maximumScale, m_pageDefinedConstraints.initialScale);
192 }
193 }
194 }
195
196 if (nonUserScalableQuirkEnabled && !description.userZoom) {
197 m_pageDefinedConstraints.initialScale = targetDensityDPIFactor;
198 m_pageDefinedConstraints.minimumScale = m_pageDefinedConstraints.initialScale;
199 m_pageDefinedConstraints.maximumScale = m_pageDefinedConstraints.initialScale;
200 if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom || description.maxWidth == Length(100, ViewportPercentageWidth)) {
201 adjustedLayoutSizeWidth = viewSize.width() / targetDensityDPIFactor;
202 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, viewSize);
203 }
204 }
205
206 m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
207 m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
208 }
209
210 } // namespace WebCore
211