commit	59146a705599a9b0742a11b3df39a15f2843a0c8	[log] [tgz]
author	mmaxfield@apple.com <mmaxfield@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>	Wed May 29 02:27:20 2019 +0000
committer	mmaxfield@apple.com <mmaxfield@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>	Wed May 29 02:27:20 2019 +0000
tree	da5d68f1b50e1f54e2fa2def6fa07aa95d08174e
parent	c7a4d2bd6abc816d5f6d7a82977e3ee9b76541d2 [diff]

Move idempotent text autosizing to StyleTreeResolver
https://bugs.webkit.org/show_bug.cgi?id=197808
<rdar://problem/50283983>

Reviewed by Antti Koivisto.

Source/WebCore:

This patch migrates the idempotent text autosizing code to live inside style resolution. This is almost
the same as the algorithm that uses the result of layout to calculate autosizing, but this version only
operates on style (and thus doesn't require double layouts). Because it is being run in an environment
with less information, autosizing is occurring in more places, so the curves have been adjusted to make
autosizing not boost as much as the previous implementation did. The new algorithm is modelled after
text-decorations-in-effect. I've claimed 4 of the unused bits in RenderStyle to contain the state of the
autosizing algorithm. StyleResolver::adjustRenderStyle() is where the algorithm is implemented:
- Look at the inherited bits
- Interogate the element's RenderStyle
- Compute new bits for the element, and set them in its RenderStyle
- Based on the newly computed bits, determine whether we should increase the text size
- If so, determine how much using the specified font size, and apply the result to the computed font size

This works because StyleBuilderCustom::applyInheritFontSize() inherits from the specified font size, not
the computed font size.

This patch also will disable autosizing using the other methods (so there aren't two methods of autosizing
fighting each other) and will honor text-size-adjust:none. However, it won't honor text-size-adjust:100%.
If content says text-size-adjust:100%, we will disregard it and take this code path.

Tests: fast/text-autosizing/ios/idempotentmode/css-exposure.html
       fast/text-autosizing/ios/idempotentmode/idempotent-autosizing-skip.html
       fast/text-autosizing/ios/idempotentmode/idempotent-autosizing-identity.html
       fast/text-autosizing/ios/idempotentmode/idempotent-autosizing.html

* Sources.txt:
* WebCore.xcodeproj/project.pbxproj:
* css/CSSComputedStyleDeclaration.cpp:
(WebCore::ComputedStyleExtractor::valueForPropertyinStyle):
* css/CSSProperties.json:
* css/StyleBuilderCustom.h:
(WebCore::computeBaseSpecifiedFontSize):
(WebCore::computeLineHeightMultiplierDueToFontSize):
* css/StyleResolver.cpp:
(WebCore::idempotentTextSize):
(WebCore::hasTextChildren):
(WebCore::StyleResolver::adjustRenderStyle):
(WebCore::StyleResolver::checkForTextSizeAdjust):
* page/FrameViewLayoutContext.cpp:
(WebCore::FrameViewLayoutContext::applyTextSizingIfNeeded):
* rendering/RenderBlockFlow.cpp:
(WebCore::RenderBlockFlow::adjustComputedFontSizes):
(WebCore::idempotentTextSize): Deleted.
* rendering/RenderBlockFlow.h:
* rendering/RenderElement.cpp:
(WebCore::includeNonFixedHeight):
(WebCore::RenderElement::adjustComputedFontSizesOnBlocks):
(WebCore::RenderElement::resetTextAutosizing):
* rendering/style/RenderStyle.cpp:
(WebCore::RenderStyle::RenderStyle):
(WebCore::RenderStyle::autosizeStatus const):
(WebCore::RenderStyle::setAutosizeStatus):
* rendering/style/RenderStyle.h:
* rendering/style/TextSizeAdjustment.cpp: Added.
(WebCore::AutosizeStatus::AutosizeStatus):
(WebCore::AutosizeStatus::contains const):
(WebCore::AutosizeStatus::modifiedStatus const):
(WebCore::AutosizeStatus::shouldSkipSubtree const):
* rendering/style/TextSizeAdjustment.h:

LayoutTests:

* fast/text-autosizing/ios/idempotentmode/css-exposure-expected.txt: Added.
* fast/text-autosizing/ios/idempotentmode/css-exposure.html: Added.
* fast/text-autosizing/ios/idempotentmode/idempotent-autosizing-skip-expected.html: Added.
* fast/text-autosizing/ios/idempotentmode/idempotent-autosizing-skip.html: Added.
* platform/ipad/fast/text-autosizing/text-size-adjust-inline-style-expected.html: Removed.
* platform/ipad/fast/text-autosizing/text-size-adjust-inline-style.html: Removed.
We're intentionally not honoring percentages, because this is the most common way that
text autosizing is disabled (by setting it to 100%) on the Web today. However, Web authors
that have done this did it without knowing the full extent of the behavior change, and
the new idempotent text autosizing code path seems to be a progression in most cases
we've seen.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@245838 268f45cc-cd09-0410-ab3c-d52691b4dbfc

23 files changed

tree: da5d68f1b50e1f54e2fa2def6fa07aa95d08174e

ReadMe.md

WebKit

WebKit is a cross-platform web browser engine. On iOS and macOS, it powers Safari, Mail, iBooks, and many other applications.

Feature Status

Visit WebKit Feature Status page to see which Web API has been implemented, in development, or under consideration.

Trying the Latest

On macOS, download Safari Technology Preview to test the latest version of WebKit. On Linux, download Epiphany Technology Preview. On Windows, you'll have to build it yourself.

Reporting Bugs

Search WebKit Bugzilla to see if there is an existing report for the bug you've encountered.
Create a Bugzilla account to to report bugs (and to comment on them) if you haven't done so already.
File a bug in accordance with our guidelines.

Once your bug is filed, you will receive email when it is updated at each stage in the bug life cycle. After the bug is considered fixed, you may be asked to download the latest nightly and confirm that the fix works for you.

Getting the Code

On Windows, follow the instructions on our website.

Cloning the Git SVN Repository

Run the following command to clone WebKit's Git SVN repository:

git clone git://git.webkit.org/WebKit.git WebKit

git clone https://git.webkit.org/git/WebKit.git WebKit

If you want to be able to commit changes to the repository, or just want to check out branches that aren’t contained in WebKit.git, you will need track WebKit's Subversion repository. You can run the following command to configure this and other options of the new Git clone for WebKit development.

Tools/Scripts/webkit-patch setup-git-clone

For information about this, and other aspects of using Git with WebKit, read the wiki page.

Checking out the Subversion Repository

If you don‘t want to use Git, run the following command to check out WebKit’s Subversion repository:

svn checkout https://svn.webkit.org/repository/webkit/trunk WebKit

Building WebKit

Building macOS Port

Install Xcode and its command line tools if you haven't done so already:

Install Xcode Get Xcode from https://developer.apple.com/downloads. To build WebKit for OS X, Xcode 5.1.1 or later is required. To build WebKit for iOS Simulator, Xcode 7 or later is required.
Install the Xcode Command Line Tools In Terminal, run the command: xcode-select --install

Run the following command to build a debug build with debugging symbols and assertions:

Tools/Scripts/build-webkit --debug

For performance testing, and other purposes, use --release instead.

Using Xcode

You can open WebKit.xcworkspace to build and debug WebKit within Xcode.

If you don't use a custom build location in Xcode preferences, you have to update the workspace settings to use WebKitBuild directory. In menu bar, choose File > Workspace Settings, then click the Advanced button, select “Custom”, “Relative to Workspace”, and enter WebKitBuild for both Products and Intermediates.

Building iOS Port

The first time after you install a new Xcode, you will need to run the following command to enable Xcode to build command line tools for iOS Simulator:

sudo Tools/Scripts/configure-xcode-for-ios-development

Without this step, you will see the error message: “target specifies product type ‘com.apple.product-type.tool’, but there’s no such product type for the ‘iphonesimulator’ platform.” when building target JSCLLIntOffsetsExtractor of project JavaScriptCore.

Run the following command to build a debug build with debugging symbols and assertions for iOS:

Tools/Scripts/build-webkit --debug --ios-simulator

Building the GTK+ Port

For production builds:

cmake -DPORT=GTK -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
ninja
sudo ninja install

For development builds:

Tools/gtk/install-dependencies
Tools/Scripts/update-webkitgtk-libs
Tools/Scripts/build-webkit --gtk --debug

For more information on building WebKitGTK+, see the wiki page.

Building the WPE Port

For production builds:

cmake -DPORT=WPE -DCMAKE_BUILD_TYPE=RelWithDebInfo -GNinja
ninja
sudo ninja install

For development builds:

Tools/wpe/install-dependencies
Tools/Scripts/update-webkitwpe-libs
Tools/Scripts/build-webkit --wpe --debug

Building Windows Port

For building WebKit on Windows, see the wiki page.

Running WebKit

With Safari and Other macOS Applications

Run the following command to launch Safari with your local build of WebKit:

Tools/Scripts/run-safari --debug

The run-safari script sets the DYLD_FRAMEWORK_PATH environment variable to point to your build products, and then launches /Applications/Safari.app. DYLD_FRAMEWORK_PATH tells the system loader to prefer your build products over the frameworks installed in /System/Library/Frameworks.

To run other applications with your local build of WebKit, run the following command:

Tools/Scripts/run-webkit-app <application-path>

iOS Simulator

Run the following command to launch iOS simulator with your local build of WebKit:

run-safari --debug --ios-simulator

In both cases, if you have built release builds instead, use --release instead of --debug.

Linux Ports

If you have a development build, you can use the run-minibrowser script, e.g.:

run-minibrowser --debug --wpe

Pass one of --gtk, --jsc-only, or --wpe to indicate the port to use.

Contribute

Congratulations! You’re up and running. Now you can begin coding in WebKit and contribute your fixes and new features to the project. For details on submitting your code to the project, read Contributing Code.