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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - Web Inspector: Nested ContentBrowsers / ContentViewContainers cause too many ContentView updates"
href="https://bugs.webkit.org/show_bug.cgi?id=146256">146256</a>
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<th>Summary</th>
<td>Web Inspector: Nested ContentBrowsers / ContentViewContainers cause too many ContentView updates
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<th>Classification</th>
<td>Unclassified
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<th>Product</th>
<td>WebKit
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<th>Version</th>
<td>528+ (Nightly build)
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<th>Hardware</th>
<td>All
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<th>OS</th>
<td>All
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>Normal
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<th>Priority</th>
<td>P2
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<th>Component</th>
<td>Web Inspector
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<th>Assignee</th>
<td>webkit-unassigned@lists.webkit.org
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<th>Reporter</th>
<td>joepeck@webkit.org
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<th>CC</th>
<td>burg@cs.washington.edu, graouts@webkit.org, joepeck@webkit.org, jonowells@apple.com, mattbaker@apple.com, nvasilyev@apple.com, timothy@apple.com, webkit-bug-importer@group.apple.com
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<pre>* SUMMARY
Nested ContentBrowsers / ContentViewContainers cause too many ContentView updates.
For resources the View hierarchy looks something like this:
- TabBrowser
- ContentViewContainer
- ResourcesTabContentView (1) (ContentBrowserTabContentView with a ContentBrowser)
- ContentViewContainer
- ResourceClusterContentView (2) (ClusterContentView)
- ContentViewContainer
- TextResourceContentView (3)
- TextEditor
In the process of showing each of the 3 ContentViews, actions are taken on its sub-views that repeat over and over depending on the nested level. ContentViewContainer.showContentView triggers BackForwardEntry.prepareToShow, and BackForwardEntry.prepareToShow triggers multiple actions which may cascade:
- _restoreFromCookie() may cascade actions to sub ContentViews
- shown() may cascade actions to sub ContentViews
- updateLayout() may cascade actions to sub ContentViews
This situation is not ideal! It would be much better to reduce duplication of work here.
* STEPS TO REPRODUCE
1. Load <<a href="http://apple.com">http://apple.com</a>>
2. Show page source (Web Inspector, Resources Tab, Main Resource selected)
3. Scroll down the text editor
4. Switch to the Elements tab
5. Switch back to the Resources tab
=> updateLayout was called 6+ times on the TextEditor
* NOTES
- Here are annotations of the different updateLayout calls I saw in this case:
1. prepareToShow ResourceClusterContentView triggers restoreFromCookie/showContentView for the TextResourceContentView (call shown false) and updateLayout
2. prepareToShow->shown ResourceClusterContentView triggers shown for the TextResourceContentView (call shown true) and updateLayout
3. prepareToShow->shown ResourceClusterContentView triggers another showContentView for TextResourceContentView (call shown false) and updateLayout
4. prepareToShow->updateLayout ResourceClusterContentView triggers another updateLayout for TextResourceContentView
5. prepareToShow->updateLayout Tab ContentView triggers another updateLayout down the cascade to TextResourceContentView
6. Left Sidebar opening (I came from Elements -> Resources) triggers another updateLayout
7. Quick Console claims it resized (probably didn't) triggers another updateLayout</pre>
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