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 namespace blink {
38
39 static const float defaultMinimumScale = 0.25f;
40 static const float defaultMaximumScale = 5.0f;
41
PageScaleConstraintsSet()42 PageScaleConstraintsSet::PageScaleConstraintsSet()
43 : m_finalConstraints(1, 1, 1)
44 , m_lastContentsWidth(0)
45 , m_needsReset(false)
46 , m_constraintsDirty(false)
47 {
48 }
49
defaultConstraints() const50 PageScaleConstraints PageScaleConstraintsSet::defaultConstraints() const
51 {
52 return PageScaleConstraints(-1, defaultMinimumScale, defaultMaximumScale);
53 }
54
updatePageDefinedConstraints(const ViewportDescription & description,Length legacyFallbackWidth)55 void PageScaleConstraintsSet::updatePageDefinedConstraints(const ViewportDescription& description, Length legacyFallbackWidth)
56 {
57 m_pageDefinedConstraints = description.resolve(m_viewSize, legacyFallbackWidth);
58
59 m_constraintsDirty = true;
60 }
61
setUserAgentConstraints(const PageScaleConstraints & userAgentConstraints)62 void PageScaleConstraintsSet::setUserAgentConstraints(const PageScaleConstraints& userAgentConstraints)
63 {
64 m_userAgentConstraints = userAgentConstraints;
65 m_constraintsDirty = true;
66 }
67
computeConstraintsStack() const68 PageScaleConstraints PageScaleConstraintsSet::computeConstraintsStack() const
69 {
70 PageScaleConstraints constraints = defaultConstraints();
71 constraints.overrideWith(m_pageDefinedConstraints);
72 constraints.overrideWith(m_userAgentConstraints);
73 return constraints;
74 }
75
computeFinalConstraints()76 void PageScaleConstraintsSet::computeFinalConstraints()
77 {
78 m_finalConstraints = computeConstraintsStack();
79
80 m_constraintsDirty = false;
81 }
82
adjustFinalConstraintsToContentsSize(IntSize contentsSize,int nonOverlayScrollbarWidth)83 void PageScaleConstraintsSet::adjustFinalConstraintsToContentsSize(IntSize contentsSize, int nonOverlayScrollbarWidth)
84 {
85 m_finalConstraints.fitToContentsWidth(contentsSize.width(), m_viewSize.width() - nonOverlayScrollbarWidth);
86 }
87
setNeedsReset(bool needsReset)88 void PageScaleConstraintsSet::setNeedsReset(bool needsReset)
89 {
90 m_needsReset = needsReset;
91 if (needsReset)
92 m_constraintsDirty = true;
93 }
94
didChangeContentsSize(IntSize contentsSize,float pageScaleFactor)95 void PageScaleConstraintsSet::didChangeContentsSize(IntSize contentsSize, float pageScaleFactor)
96 {
97 // If a large fixed-width element expanded the size of the document late in
98 // loading and our initial scale is not set (or set to be less than the last
99 // minimum scale), reset the page scale factor to the new initial scale.
100 if (contentsSize.width() > m_lastContentsWidth
101 && pageScaleFactor == finalConstraints().minimumScale
102 && computeConstraintsStack().initialScale < finalConstraints().minimumScale)
103 setNeedsReset(true);
104
105 m_constraintsDirty = true;
106 m_lastContentsWidth = contentsSize.width();
107 }
108
computeDeprecatedTargetDensityDPIFactor(const ViewportDescription & description,float deviceScaleFactor)109 static float computeDeprecatedTargetDensityDPIFactor(const ViewportDescription& description, float deviceScaleFactor)
110 {
111 if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueDeviceDPI)
112 return 1.0f / deviceScaleFactor;
113
114 float targetDPI = -1.0f;
115 if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueLowDPI)
116 targetDPI = 120.0f;
117 else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueMediumDPI)
118 targetDPI = 160.0f;
119 else if (description.deprecatedTargetDensityDPI == ViewportDescription::ValueHighDPI)
120 targetDPI = 240.0f;
121 else if (description.deprecatedTargetDensityDPI != ViewportDescription::ValueAuto)
122 targetDPI = description.deprecatedTargetDensityDPI;
123 return targetDPI > 0 ? 160.0f / targetDPI : 1.0f;
124 }
125
getLayoutWidthForNonWideViewport(const FloatSize & deviceSize,float initialScale)126 static float getLayoutWidthForNonWideViewport(const FloatSize& deviceSize, float initialScale)
127 {
128 return initialScale == -1 ? deviceSize.width() : deviceSize.width() / initialScale;
129 }
130
computeHeightByAspectRatio(float width,const FloatSize & deviceSize)131 static float computeHeightByAspectRatio(float width, const FloatSize& deviceSize)
132 {
133 return width * (deviceSize.height() / deviceSize.width());
134 }
135
didChangeViewSize(const IntSize & size)136 void PageScaleConstraintsSet::didChangeViewSize(const IntSize& size)
137 {
138 if (m_viewSize == size)
139 return;
140
141 m_viewSize = size;
142 m_constraintsDirty = true;
143 }
144
mainFrameSize(const IntSize & contentsSize) const145 IntSize PageScaleConstraintsSet::mainFrameSize(const IntSize& contentsSize) const
146 {
147 // If there's no explicit minimum scale factor set, size the frame so that its width == content width
148 // so there's no horizontal scrolling at the minimum scale.
149 if (m_pageDefinedConstraints.minimumScale < finalConstraints().minimumScale
150 && m_userAgentConstraints.minimumScale < finalConstraints().minimumScale
151 && contentsSize.width()
152 && m_viewSize.width())
153 return IntSize(contentsSize.width(), computeHeightByAspectRatio(contentsSize.width(), m_viewSize));
154
155 // If there is a minimum scale (or there's no content size yet), the frame size should match the viewport
156 // size at minimum scale, since the viewport must always be contained by the frame.
157 IntSize frameSize(m_viewSize);
158 frameSize.scale(1 / finalConstraints().minimumScale);
159 return frameSize;
160 }
161
adjustForAndroidWebViewQuirks(const ViewportDescription & description,int layoutFallbackWidth,float deviceScaleFactor,bool supportTargetDensityDPI,bool wideViewportQuirkEnabled,bool useWideViewport,bool loadWithOverviewMode,bool nonUserScalableQuirkEnabled)162 void PageScaleConstraintsSet::adjustForAndroidWebViewQuirks(const ViewportDescription& description, int layoutFallbackWidth, float deviceScaleFactor, bool supportTargetDensityDPI, bool wideViewportQuirkEnabled, bool useWideViewport, bool loadWithOverviewMode, bool nonUserScalableQuirkEnabled)
163 {
164 if (!supportTargetDensityDPI && !wideViewportQuirkEnabled && loadWithOverviewMode && !nonUserScalableQuirkEnabled)
165 return;
166
167 const float oldInitialScale = m_pageDefinedConstraints.initialScale;
168 if (!loadWithOverviewMode) {
169 bool resetInitialScale = false;
170 if (description.zoom == -1) {
171 if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom)
172 resetInitialScale = true;
173 if (useWideViewport || description.maxWidth.type() == DeviceWidth)
174 resetInitialScale = true;
175 }
176 if (resetInitialScale)
177 m_pageDefinedConstraints.initialScale = 1.0f;
178 }
179
180 float adjustedLayoutSizeWidth = m_pageDefinedConstraints.layoutSize.width();
181 float adjustedLayoutSizeHeight = m_pageDefinedConstraints.layoutSize.height();
182 float targetDensityDPIFactor = 1.0f;
183
184 if (supportTargetDensityDPI) {
185 targetDensityDPIFactor = computeDeprecatedTargetDensityDPIFactor(description, deviceScaleFactor);
186 if (m_pageDefinedConstraints.initialScale != -1)
187 m_pageDefinedConstraints.initialScale *= targetDensityDPIFactor;
188 if (m_pageDefinedConstraints.minimumScale != -1)
189 m_pageDefinedConstraints.minimumScale *= targetDensityDPIFactor;
190 if (m_pageDefinedConstraints.maximumScale != -1)
191 m_pageDefinedConstraints.maximumScale *= targetDensityDPIFactor;
192 if (wideViewportQuirkEnabled && (!useWideViewport || description.maxWidth.type() == DeviceWidth)) {
193 adjustedLayoutSizeWidth /= targetDensityDPIFactor;
194 adjustedLayoutSizeHeight /= targetDensityDPIFactor;
195 }
196 }
197
198 if (wideViewportQuirkEnabled) {
199 if (useWideViewport && (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom != 1.0f) {
200 adjustedLayoutSizeWidth = layoutFallbackWidth;
201 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
202 } else if (!useWideViewport) {
203 const float nonWideScale = description.zoom < 1 && description.maxWidth.type() != DeviceWidth && description.maxWidth.type() != DeviceHeight ? -1 : oldInitialScale;
204 adjustedLayoutSizeWidth = getLayoutWidthForNonWideViewport(m_viewSize, nonWideScale) / targetDensityDPIFactor;
205 float newInitialScale = targetDensityDPIFactor;
206 if (m_userAgentConstraints.initialScale != -1 && (description.maxWidth.type() == DeviceWidth || ((description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom) && description.zoom == -1))) {
207 adjustedLayoutSizeWidth /= m_userAgentConstraints.initialScale;
208 newInitialScale = m_userAgentConstraints.initialScale;
209 }
210 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
211 if (description.zoom < 1) {
212 m_pageDefinedConstraints.initialScale = newInitialScale;
213 if (m_pageDefinedConstraints.minimumScale != -1)
214 m_pageDefinedConstraints.minimumScale = std::min<float>(m_pageDefinedConstraints.minimumScale, m_pageDefinedConstraints.initialScale);
215 if (m_pageDefinedConstraints.maximumScale != -1)
216 m_pageDefinedConstraints.maximumScale = std::max<float>(m_pageDefinedConstraints.maximumScale, m_pageDefinedConstraints.initialScale);
217 }
218 }
219 }
220
221 if (nonUserScalableQuirkEnabled && !description.userZoom) {
222 m_pageDefinedConstraints.initialScale = targetDensityDPIFactor;
223 m_pageDefinedConstraints.minimumScale = m_pageDefinedConstraints.initialScale;
224 m_pageDefinedConstraints.maximumScale = m_pageDefinedConstraints.initialScale;
225 if (description.maxWidth.isAuto() || description.maxWidth.type() == ExtendToZoom || description.maxWidth.type() == DeviceWidth) {
226 adjustedLayoutSizeWidth = m_viewSize.width() / targetDensityDPIFactor;
227 adjustedLayoutSizeHeight = computeHeightByAspectRatio(adjustedLayoutSizeWidth, m_viewSize);
228 }
229 }
230
231 m_pageDefinedConstraints.layoutSize.setWidth(adjustedLayoutSizeWidth);
232 m_pageDefinedConstraints.layoutSize.setHeight(adjustedLayoutSizeHeight);
233 }
234
235 } // namespace blink
236