[iOS] Suppress native selection behaviors when focusing a very small editable element
authorwenson_hsieh@apple.com <wenson_hsieh@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Sun, 23 Dec 2018 06:38:24 +0000 (06:38 +0000)
committerwenson_hsieh@apple.com <wenson_hsieh@apple.com@268f45cc-cd09-0410-ab3c-d52691b4dbfc>
Sun, 23 Dec 2018 06:38:24 +0000 (06:38 +0000)
commit266176b22d3a774af8e76601cda38c55896a1072
tree9d688adab1563193fb9cd42cfd180e97253b9515
parentbab617583db1004922ae7ae896f9e107755642d6
[iOS] Suppress native selection behaviors when focusing a very small editable element
https://bugs.webkit.org/show_bug.cgi?id=193005
<rdar://problem/46583527>

Reviewed by Tim Horton.

Source/WebKit:

In r238146, I added a mechanism to detect when the selection is hidden within transparent editable elements, and
used this to suppress native selection on iOS (such as selection handles, highlight, callout bar, etc.) to avoid
conflicts between the page's editing UI and the platform.

However, one additional technique observed on some websites involves hiding the selection by moving it into a
tiny (1x1) editable element. Here, we currently still present a callout bar with editing actions, as well as
show a selection caret or handles on iOS. To fix this, we extend the mechanism added in r238146 by also
suppressing the selection assistant in the case where the editable element's area is beneath a tiny minimum
threshold.

Test: editing/selection/ios/hide-selection-in-tiny-contenteditable.html

* Shared/EditorState.cpp:
(WebKit::EditorState::PostLayoutData::encode const):
(WebKit::EditorState::PostLayoutData::decode):
(WebKit::operator<<):
* Shared/EditorState.h:

Rename selectionClipRect to focusedElementRect. We currently propagate the bounds of the focused element to the
UI process through EditorState updates, but only for the purpose of returning it in the computed selection clip
rect; instead, rename this member to something more general-purpose, so we can also use it when determining
whether to suppress the selection assistant.

* UIProcess/API/Cocoa/WKWebView.mm:
(-[WKWebView _candidateRect]):
* UIProcess/Cocoa/WebViewImpl.mm:
(WebKit::WebViewImpl::handleRequestedCandidates):
* UIProcess/ios/WKContentViewInteraction.h:

Add a new SuppressSelectionAssistantReason that corresponds to focusing tiny editable elements.

* UIProcess/ios/WKContentViewInteraction.mm:
(-[WKContentView _zoomToRevealFocusedElement]):
(-[WKContentView _selectionClipRect]):
(-[WKContentView _elementDidFocus:userIsInteracting:blurPreviousNode:changingActivityState:userObject:]):
(-[WKContentView _updateChangedSelection:]):

Check the size of the focused element, and begin or stop suppressing the selection assistant accordingly.

* WebProcess/WebPage/ios/WebPageIOS.mm:
(WebKit::WebPage::platformEditorState const):
* WebProcess/WebPage/mac/WebPageMac.mm:
(WebKit::WebPage::platformEditorState const):

LayoutTests:

Add a new layout test to verify that native selection UI is suppressed when focusing a tiny (1px by 1px)
editable element.

* editing/selection/ios/hide-selection-in-tiny-contenteditable-expected.txt: Added.
* editing/selection/ios/hide-selection-in-tiny-contenteditable.html: Added.
* resources/ui-helper.js:
(window.UIHelper.zoomToScale):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@239543 268f45cc-cd09-0410-ab3c-d52691b4dbfc
13 files changed:
LayoutTests/ChangeLog
LayoutTests/editing/selection/ios/hide-selection-in-tiny-contenteditable-expected.txt [new file with mode: 0644]
LayoutTests/editing/selection/ios/hide-selection-in-tiny-contenteditable.html [new file with mode: 0644]
LayoutTests/resources/ui-helper.js
Source/WebKit/ChangeLog
Source/WebKit/Shared/EditorState.cpp
Source/WebKit/Shared/EditorState.h
Source/WebKit/UIProcess/API/Cocoa/WKWebView.mm
Source/WebKit/UIProcess/Cocoa/WebViewImpl.mm
Source/WebKit/UIProcess/ios/WKContentViewInteraction.h
Source/WebKit/UIProcess/ios/WKContentViewInteraction.mm
Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm
Source/WebKit/WebProcess/WebPage/mac/WebPageMac.mm