Changeset 246852 in webkit

Timestamp:

Jun 26, 2019 4:10:21 PM (5 years ago)

Author:

Wenson Hsieh

Message:

[iPadOS] eddm.usps.com scrolls horizontally due to explicit width set in viewport meta tag
​https://bugs.webkit.org/show_bug.cgi?id=199219
<rdar://problem/50425765>

Reviewed by Tim Horton.

Source/WebKit:

Currently, the heuristic to determine whether the page should be shrunk to fit the content width after loading
works by checking whether the page's content is wider than the layout width we've provided for the page.
However, in the case where an explicit width larger than the true view width is specified by the page's meta
viewport, we'll end up believing that the page's content is not wider than the layout width, which is dictated
by the fixed meta viewport width. Instead, we can shrink the page down in this scenario by comparing the content
width against the scaled size of the view when computing the amount of horizontal overflow.

Test: fast/viewport/ios/shrink-to-fit-content-large-constant-width.html

• WebProcess/WebPage/ios/WebPageIOS.mm:

(WebKit::WebPage::immediatelyShrinkToFitContent):

LayoutTests:

Add a new test to verify that if the meta viewport tag specifies a wide fixed width value, we will still try to
shrink the page down to fit within the viewport.

• fast/viewport/ios/shrink-to-fit-content-large-constant-width-expected.txt: Added.
• fast/viewport/ios/shrink-to-fit-content-large-constant-width.html: Added.

Location:

trunk

Files:

• LayoutTests/ChangeLog (modified) (1 diff)
• LayoutTests/fast/viewport/ios/shrink-to-fit-content-large-constant-width-expected.txt (added)
• LayoutTests/fast/viewport/ios/shrink-to-fit-content-large-constant-width.html (added)
• Source/WebKit/ChangeLog (modified) (1 diff)
• Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm (modified) (2 diffs)

trunk/LayoutTests/ChangeLog

@@ +1 @@
+2019-06-26  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        [iPadOS] eddm.usps.com scrolls horizontally due to explicit width set in viewport meta tag
+        https://bugs.webkit.org/show_bug.cgi?id=199219
+        <rdar://problem/50425765>
+
+        Reviewed by Tim Horton.
+
+        Add a new test to verify that if the meta viewport tag specifies a wide fixed width value, we will still try to
+        shrink the page down to fit within the viewport.
+
+        * fast/viewport/ios/shrink-to-fit-content-large-constant-width-expected.txt: Added.
+        * fast/viewport/ios/shrink-to-fit-content-large-constant-width.html: Added.
+
 2019-06-26  Joseph Pecoraro  <pecoraro@apple.com>
 

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2019-06-26  Wenson Hsieh  <wenson_hsieh@apple.com>
+
+        [iPadOS] eddm.usps.com scrolls horizontally due to explicit width set in viewport meta tag
+        https://bugs.webkit.org/show_bug.cgi?id=199219
+        <rdar://problem/50425765>
+
+        Reviewed by Tim Horton.
+
+        Currently, the heuristic to determine whether the page should be shrunk to fit the content width after loading
+        works by checking whether the page's content is wider than the layout width we've provided for the page.
+        However, in the case where an explicit width larger than the true view width is specified by the page's meta
+        viewport, we'll end up believing that the page's content is not wider than the layout width, which is dictated
+        by the fixed meta viewport width. Instead, we can shrink the page down in this scenario by comparing the content
+        width against the scaled size of the view when computing the amount of horizontal overflow.
+
+        Test: fast/viewport/ios/shrink-to-fit-content-large-constant-width.html
+
+        * WebProcess/WebPage/ios/WebPageIOS.mm:
+        (WebKit::WebPage::immediatelyShrinkToFitContent):
+
 2019-06-26  Zalan Bujtas  <zalan@apple.com>
 

trunk/Source/WebKit/WebProcess/WebPage/ios/WebPageIOS.mm

@@ -3318 +3318 @@
     static const int toleratedHorizontalScrollingDistance = 20;
     static const int maximumExpandedLayoutWidth = 1280;
+
+    auto scaledViewWidth = [&] () -> int {
+        return std::round(m_viewportConfiguration.viewLayoutSize().width() / m_viewportConfiguration.initialScale());
+    };
+
     int originalContentWidth = view->contentsWidth();
+    int originalViewWidth = scaledViewWidth();
     int originalLayoutWidth = m_viewportConfiguration.layoutWidth();
-    int originalHorizontalOverflowAmount = originalContentWidth - originalLayoutWidth;
-    if (originalHorizontalOverflowAmount <= toleratedHorizontalScrollingDistance || originalLayoutWidth >= maximumExpandedLayoutWidth || originalContentWidth <= m_viewportConfiguration.viewLayoutSize().width())
+    int originalHorizontalOverflowAmount = originalContentWidth - originalViewWidth;
+    if (originalHorizontalOverflowAmount <= toleratedHorizontalScrollingDistance || originalLayoutWidth >= maximumExpandedLayoutWidth || originalContentWidth <= originalViewWidth)
         return false;
 
@@ -3335 +3341 @@
     m_viewportConfiguration.setIsKnownToLayOutWiderThanViewport(true);
     double originalMinimumDeviceWidth = m_viewportConfiguration.minimumEffectiveDeviceWidth();
-    if (changeMinimumEffectiveDeviceWidth(std::min(maximumExpandedLayoutWidth, originalContentWidth)) && view->contentsWidth() - m_viewportConfiguration.layoutWidth() > originalHorizontalOverflowAmount) {
+    if (changeMinimumEffectiveDeviceWidth(std::min(maximumExpandedLayoutWidth, originalContentWidth)) && view->contentsWidth() - scaledViewWidth() > originalHorizontalOverflowAmount) {
         changeMinimumEffectiveDeviceWidth(originalMinimumDeviceWidth);
         m_viewportConfiguration.setIsKnownToLayOutWiderThanViewport(false);