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 "web/PageScaleConstraintsSet.h"
33
34 #include "platform/Length.h"
35 #include "wtf/Assertions.h"
36
37 using namespace WebCore;
38
39 namespace blink {
40
41 static const float defaultMinimumScale = 0.25f;
42 static const float defaultMaximumScale = 5.0f;
43
PageScaleConstraintsSet()44 PageScaleConstraintsSet::PageScaleConstraintsSet()
45 : m_lastContentsWidth(0)
46 , m_needsReset(false)
47 , m_constraintsDirty(false)
48 {
49 m_finalConstraints = defaultConstraints();
50 }
51
defaultConstraints() const52 PageScaleConstraints PageScaleConstraintsSet::defaultConstraints() const
53 {
54 return PageScaleConstraints(-1, defaultMinimumScale, defaultMaximumScale);
55 }
56
updatePageDefinedConstraints(const ViewportDescription & description,Length legacyFallbackWidth)57 void PageScaleConstraintsSet::updatePageDefinedConstraints(const ViewportDescription& description, Length legacyFallbackWidth)
58 {
59 m_pageDefinedConstraints = description.resolve(m_viewSize, legacyFallbackWidth);
60
61 m_constraintsDirty = true;
62 }
63
setUserAgentConstraints(const PageScaleConstraints & userAgentConstraints)64 void PageScaleConstraintsSet::setUserAgentConstraints(const PageScaleConstraints& userAgentConstraints)
65 {
66 m_userAgentConstraints = userAgentConstraints;
67 m_constraintsDirty = true;
68 }
69
computeConstraintsStack() const70 PageScaleConstraints PageScaleConstraintsSet::computeConstraintsStack() const
71 {
72 PageScaleConstraints constraints = defaultConstraints();
73 constraints.overrideWith(m_pageDefinedConstraints);
74 constraints.overrideWith(m_userAgentConstraints);
75 return constraints;
76 }
77
computeFinalConstraints()78 void PageScaleConstraintsSet::computeFinalConstraints()
79 {
80 m_finalConstraints = computeConstraintsStack();
81
82 m_constraintsDirty = false;
83 }
84
adjustFinalConstraintsToContentsSize(IntSize contentsSize,int nonOverlayScrollbarWidth)85 void PageScaleConstraintsSet::adjustFinalConstraintsToContentsSize(IntSize contentsSize, int nonOverlayScrollbarWidth)
86 {
87 m_finalConstraints.fitToContentsWidth(contentsSize.width(), m_viewSize.width() - nonOverlayScrollbarWidth);
88 }
89
setNeedsReset(bool needsReset)90 void PageScaleConstraintsSet::setNeedsReset(bool needsReset)
91 {
92 m_needsReset = needsReset;
93 if (needsReset)
94 m_constraintsDirty = true;
95 }
96
didChangeContentsSize(IntSize contentsSize,float pageScaleFactor)97 void PageScaleConstraintsSet::didChangeContentsSize(IntSize contentsSize, float pageScaleFactor)
98 {
99 // If a large fixed-width element expanded the size of the document late in
100 // loading and our initial scale is not set (or set to be less than the last
101 // minimum scale), reset the page scale factor to the new initial scale.
102 if (contentsSize.width() > m_lastContentsWidth
103 && pageScaleFactor == finalConstraints().minimumScale
104 && computeConstraintsStack().initialScale < finalConstraints().minimumScale)
105 setNeedsReset(true);
106
107 m_constraintsDirty = true;
108 m_lastContentsWidth = contentsSize.width();
109 }
110
computeDeprecatedTargetDensityDPIFactor(const ViewportDescription & description,float deviceScaleFactor)111 static float computeDeprecatedTargetDensityDPIFactor(const ViewportDescription& description, float deviceScaleFactor)
112 {
113 if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueDeviceDPI)
114 return 1.0f / deviceScaleFactor;
115
116 float targetDPI = -1.0f;
117 if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueLowDPI)
118 targetDPI = 120.0f;
119 else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueMediumDPI)
120 targetDPI = 160.0f;
121 else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueHighDPI)
122 targetDPI = 240.0f;
123 else if (description.deprecatedTargetDensityDPI != ViewportDescription::ValueAuto)
124 targetDPI = description.deprecatedTargetDensityDPI;
125 return targetDPI > 0 ? 160.0f / targetDPI : 1.0f;
126 }
127
getLayoutWidthForNonWideViewport(const FloatSize & deviceSize,float initialScale)128 static float getLayoutWidthForNonWideViewport(const FloatSize& deviceSize, float initialScale)
129 {
130 return initialScale == -1 ? deviceSize.width() : deviceSize.width() / initialScale;
131 }
132
computeHeightByAspectRatio(float width,const FloatSize & deviceSize)133 static float computeHeightByAspectRatio(float width, const FloatSize& deviceSize)
134 {
135 return width * (deviceSize.height() / deviceSize.width());
136 }
137
didChangeViewSize(const IntSize & size)138 void PageScaleConstraintsSet::didChangeViewSize(const IntSize& size)
139 {
140 if (m_viewSize == size)
141 return;
142
143 m_viewSize = size;
144 m_constraintsDirty = true;
145 }
146
mainFrameSize(const IntSize & contentsSize) const147 IntSize PageScaleConstraintsSet::mainFrameSize(const IntSize& contentsSize) const
148 {
149 // If there's no explicit minimum scale factor set, size the frame so that its width == content width
150 // so there's no horizontal scrolling at the minimum scale.
151 if (m_pageDefinedConstraints.minimumScale < finalConstraints().minimumScale
152 && m_userAgentConstraints.minimumScale < finalConstraints().minimumScale
153 && contentsSize.width()
154 && m_viewSize.width())
155 return IntSize(contentsSize.width(), computeHeightByAspectRatio(contentsSize.width(), m_viewSize));
156
157 // If there is a minimum scale (or there's no content size yet), the frame size should match the viewport
158 // size at minimum scale, since the viewport must always be contained by the frame.
159 IntSize frameSize(m_viewSize);
160 frameSize.scale(1 / finalConstraints().minimumScale);
161 return frameSize;
162 }
163
adjustForAndroidWebViewQuirks(const ViewportDescription & description,int layoutFallbackWidth,float deviceScaleFactor,bool supportTargetDensityDPI,bool wideViewportQuirkEnabled,bool useWideViewport,bool loadWithOverviewMode,bool nonUserScalableQuirkEnabled)164 void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode, bool nonUserScalableQuirkEnabled)
165 {
166 if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode && !nonUserScalableQuirkEnabled)
167 return;
168
169 const float oldInitialScale = m_pageDefinedConstraints.initialScale;
170 if (!loadWithOverviewMode) {
171 bool resetInitialScale = false;
172 if (description.zoom == -1) {
173 if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom)
174 resetInitialScale = true;
175 if (useWideViewport || description.maxWidth.type() == DeviceWidth)
176 resetInitialScale = true;
177 }
178 if (resetInitialScale)
179 m_pageDefinedConstraints.initialScale = 1.0f;
180 }
181
182 float adjustedLayoutSizeWidth = m_pageDefinedConstraints.layoutSize.width();
183 float adjustedLayoutSizeHeight = m_pageDefinedConstraints.layoutSize.height();
184 float targetDensityDPIFactor = 1.0f;
185
186 if (supportTargetDensityDPI) {
187 targetDensityDPIFactor = computeDeprecatedTargetDensityDPIFactor(description, deviceScaleFactor);
188 if (m_pageDefinedConstraints.initialScale != -1)
189 m_pageDefinedConstraints.initialScale *= targetDensityDPIFactor;
190 if (m_pageDefinedConstraints.minimumScale != -1)
191 m_pageDefinedConstraints.minimumScale *= targetDensityDPIFactor;
192 if (m_pageDefinedConstraints.maximumScale != -1)
193 m_pageDefinedConstraints.maximumScale *= targetDensityDPIFactor;
194 if (wideViewportQuirkEnabled && (!useWideViewport || description.maxWidth.type() == DeviceWidth)) {
195 adjustedLayoutSizeWidth /= targetDensityDPIFactor;
196 adjustedLayoutSizeHeight /= targetDensityDPIFactor;
197 }
198 }
199
200 if (wideViewportQuirkEnabled) {
201 if (useWideViewport && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom != 1.0f) {
202 adjustedLayoutSizeWidth = layoutFallbackWidth;
203 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
204 } else if (!useWideViewport) {
205 const float nonWideScale = description.zoom < 1 && description.maxWidth.type() != DeviceWidth && description.maxWidth.type() != DeviceHeight ? -1 : oldInitialScale;
206 adjustedLayoutSizeWidth = getLayoutWidthForNonWideViewport(m_viewSize, nonWideScale) / targetDensityDPIFactor;
207 float newInitialScale = targetDensityDPIFactor;
208 if (m_userAgentConstraints.initialScale != -1 && (description.maxWidth.type() == DeviceWidth || ((description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom == -1))) {
209 adjustedLayoutSizeWidth /= m_userAgentConstraints.initialScale;
210 newInitialScale = m_userAgentConstraints.initialScale;
211 }
212 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
213 if (description.zoom < 1) {
214 m_pageDefinedConstraints.initialScale = newInitialScale;
215 if (m_pageDefinedConstraints.minimumScale != -1)
216 m_pageDefinedConstraints.minimumScale = std::min<float>(m_pageDefinedConstraints.minimumScale, m_pageDefinedConstraints.initialScale);
217 if (m_pageDefinedConstraints.maximumScale != -1)
218 m_pageDefinedConstraints.maximumScale = std::max<float>(m_pageDefinedConstraints.maximumScale, m_pageDefinedConstraints.initialScale);
219 }
220 }
221 }
222
223 if (nonUserScalableQuirkEnabled && !description.userZoom) {
224 m_pageDefinedConstraints.initialScale = targetDensityDPIFactor;
225 m_pageDefinedConstraints.minimumScale = m_pageDefinedConstraints.initialScale;
226 m_pageDefinedConstraints.maximumScale = m_pageDefinedConstraints.initialScale;
227 if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom || description.maxWidth.type() == DeviceWidth) {
228 adjustedLayoutSizeWidth = m_viewSize.width() / targetDensityDPIFactor;
229 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
230 }
231 }
232
233 m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
234 m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
235 }
236
237 } // namespace WebCore
238