Bug 1263357 - When the caret is placed after visible line break, associate caret with frame on the next line instead. r=mats

--HG--
extra : amend_source : a0068b0c841189204e07cc6c0a19f83d5dac8da3

dom/base/nsDocumentEncoder.cpp

@@ -49,9 +49,7 @@
 #include "mozilla/dom/Element.h"
 #include "mozilla/dom/ShadowRoot.h"
 #include "mozilla/dom/EncodingUtils.h"
-#include "nsContainerFrame.h"
-#include "nsBlockFrame.h"
-#include "nsComputedDOMStyle.h"
+#include "nsLayoutUtils.h"
 
 using namespace mozilla;
 using namespace mozilla::dom;
@@ -324,85 +322,6 @@ nsDocumentEncoder::IncludeInContext(nsINode *aNode)
   return false;
 }
 
-static
-bool
-LineHasNonEmptyContentWorker(nsIFrame* aFrame)
-{
-  // Look for non-empty frames, but ignore inline and br frames.
-  // For inline frames, descend into the children, if any.
-  if (aFrame->GetType() == nsGkAtoms::inlineFrame) {
-    for (nsIFrame* child : aFrame->PrincipalChildList()) {
-      if (LineHasNonEmptyContentWorker(child)) {
-        return true;
-      }
-    }
-  } else {
-    if (aFrame->GetType() != nsGkAtoms::brFrame &&
-        !aFrame->IsEmpty()) {
-      return true;
-    }
-  }
-  return false;
-}
-
-static
-bool
-LineHasNonEmptyContent(nsLineBox* aLine)
-{
-  int32_t count = aLine->GetChildCount();
-  for (nsIFrame* frame = aLine->mFirstChild; count > 0;
-       --count, frame = frame->GetNextSibling()) {
-    if (LineHasNonEmptyContentWorker(frame)) {
-      return true;
-    }
-  }
-  return false;
-}
-
-static
-bool
-IsInvisibleBreak(nsINode *aNode)
-{
-  if (!aNode->IsElement() || !aNode->IsEditable()) {
-    return false;
-  }
-  nsIFrame* frame = aNode->AsElement()->GetPrimaryFrame();
-  if (!frame || frame->GetType() != nsGkAtoms::brFrame) {
-    return false;
-  }
-
-  nsContainerFrame* f = frame->GetParent();
-  while (f && f->IsFrameOfType(nsBox::eLineParticipant)) {
-    f = f->GetParent();
-  }
-  nsBlockFrame* blockAncestor = do_QueryFrame(f);
-  if (!blockAncestor) {
-    // The container frame doesn't support line breaking.
-    return false;
-  }
-
-  bool valid = false;
-  nsBlockInFlowLineIterator iter(blockAncestor, frame, &valid);
-  if (!valid) {
-    return false;
-  }
-
-  bool lineNonEmpty = LineHasNonEmptyContent(iter.GetLine());
-
-  while (iter.Next()) {
-    auto currentLine = iter.GetLine();
-    // Completely skip empty lines.
-    if (!currentLine->IsEmpty()) {
-      // If we come across an inline line, the BR has caused a visible line break.
-      if (currentLine->IsInline()) {
-        return false;
-      }
-    }
-  }
-
-  return lineNonEmpty;
-}
-
 nsresult
 nsDocumentEncoder::SerializeNodeStart(nsINode* aNode,
                                       int32_t aStartOffset,
@@ -437,7 +356,7 @@ nsDocumentEncoder::SerializeNodeStart(nsINode* aNode,
   if (node->IsElement()) {
     if ((mFlags & (nsIDocumentEncoder::OutputPreformatted |
                    nsIDocumentEncoder::OutputDropInvisibleBreak)) &&
-        IsInvisibleBreak(node)) {
+        nsLayoutUtils::IsInvisibleBreak(node)) {
       return NS_OK;
     }
     Element* originalElement =

layout/base/nsLayoutUtils.cpp

@@ -9370,3 +9370,92 @@ nsLayoutUtils::SupportsServoStyleBackend(nsIDocument* aDocument)
          aDocument->IsHTMLOrXHTML() &&
          static_cast<nsDocument*>(aDocument)->IsContentDocument();
 }
+
+static
+bool
+LineHasNonEmptyContentWorker(nsIFrame* aFrame)
+{
+  // Look for non-empty frames, but ignore inline and br frames.
+  // For inline frames, descend into the children, if any.
+  if (aFrame->GetType() == nsGkAtoms::inlineFrame) {
+    for (nsIFrame* child : aFrame->PrincipalChildList()) {
+      if (LineHasNonEmptyContentWorker(child)) {
+        return true;
+      }
+    }
+  } else {
+    if (aFrame->GetType() != nsGkAtoms::brFrame &&
+        !aFrame->IsEmpty()) {
+      return true;
+    }
+  }
+  return false;
+}
+
+static
+bool
+LineHasNonEmptyContent(nsLineBox* aLine)
+{
+  int32_t count = aLine->GetChildCount();
+  for (nsIFrame* frame = aLine->mFirstChild; count > 0;
+       --count, frame = frame->GetNextSibling()) {
+    if (LineHasNonEmptyContentWorker(frame)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/* static */ bool
+nsLayoutUtils::IsInvisibleBreak(nsINode* aNode, nsIFrame** aNextLineFrame)
+{
+  if (aNextLineFrame) {
+    *aNextLineFrame = nullptr;
+  }
+
+  if (!aNode->IsElement() || !aNode->IsEditable()) {
+    return false;
+  }
+  nsIFrame* frame = aNode->AsElement()->GetPrimaryFrame();
+  if (!frame || frame->GetType() != nsGkAtoms::brFrame) {
+    return false;
+  }
+
+  nsContainerFrame* f = frame->GetParent();
+  while (f && f->IsFrameOfType(nsBox::eLineParticipant)) {
+    f = f->GetParent();
+  }
+  nsBlockFrame* blockAncestor = do_QueryFrame(f);
+  if (!blockAncestor) {
+    // The container frame doesn't support line breaking.
+    return false;
+  }
+
+  bool valid = false;
+  nsBlockInFlowLineIterator iter(blockAncestor, frame, &valid);
+  if (!valid) {
+    return false;
+  }
+
+  bool lineNonEmpty = LineHasNonEmptyContent(iter.GetLine());
+  if (!lineNonEmpty) {
+    return false;
+  }
+
+  while (iter.Next()) {
+    auto currentLine = iter.GetLine();
+    // Completely skip empty lines.
+    if (!currentLine->IsEmpty()) {
+      // If we come across an inline line, the BR has caused a visible line break.
+      if (currentLine->IsInline()) {
+        if (aNextLineFrame) {
+          *aNextLineFrame = currentLine->mFirstChild;
+        }
+        return false;
+      }
+      break;
+    }
+  }
+
+  return lineNonEmpty;
+}

layout/base/nsLayoutUtils.h

@@ -2856,6 +2856,19 @@ public:
    */
   static bool SupportsServoStyleBackend(nsIDocument* aDocument);
 
+  /*
+   * Checks whether a node is an invisible break.
+   * If not, returns the first frame on the next line if such a next line exists.
+   *
+   * @return  true if the node is an invisible break.
+   *          aNextLineFrame is returned null in this case.
+   *          false if the node causes a visible break or if the node is no break.
+   *
+   * @param   aNextLineFrame  assigned to first frame on the next line if such a
+   *                          next line exists, null otherwise.
+   */
+  static bool IsInvisibleBreak(nsINode* aNode, nsIFrame** aNextLineFrame = nullptr);
+
 private:
   static uint32_t sFontSizeInflationEmPerLine;
   static uint32_t sFontSizeInflationMinTwips;

layout/base/tests/bug1263357-1-ref.html

@@ -0,0 +1,28 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #1 for bug 1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><p id="theP"><tt>xyz<br></tt><br></p></div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theP = document.getElementById("theP");
+  theDiv.focus();
+  sel.collapse(theP, 1);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-1.html

@@ -0,0 +1,34 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=bug1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #1 for bug1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><p><tt>xyz</tt><br></p></div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theDiv.focus();
+  sel.collapse(theDiv, 0);
+  if (navigator.platform.indexOf("Win") == 0) {
+    synthesizeKey("VK_END", {});
+  } else {
+    // End key doesn't work as expected on Mac and Linux.
+    sel.modify("move", "right", "lineboundary");
+  }
+  synthesizeKey("VK_RETURN", {shiftKey: true});
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-2-ref.html

@@ -0,0 +1,28 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #2 for bug 1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><p id="theP"><font color=red><span>xyz<br></span></font><br></p></div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theP = document.getElementById("theP");
+  theDiv.focus();
+  sel.collapse(theP, 1);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-2.html

@@ -0,0 +1,34 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=bug1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #2 for bug 1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><p><font color=red><span>xyz</span></font><br></p></div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theDiv.focus();
+  sel.collapse(theDiv, 0);
+  if (navigator.platform.indexOf("Win") == 0) {
+    synthesizeKey("VK_END", {});
+  } else {
+    // End key doesn't work as expected on Mac and Linux.
+    sel.modify("move", "right", "lineboundary");
+  }
+  synthesizeKey("VK_RETURN", {shiftKey: true});
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-3-ref.html

@@ -0,0 +1,27 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #3 for bug 1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><span id="theSpan">text<br></span><br>more</div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theDiv.focus();
+  sel.collapse(theDiv, 1);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-3.html

@@ -0,0 +1,28 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=bug1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #3 for bug1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><span id="theSpan">text<br></span><br>more</div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theSpan = document.getElementById("theSpan");
+  theDiv.focus();
+  sel.collapse(theSpan, 2);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-4-ref.html

@@ -0,0 +1,27 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #4 for bug 1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><span id="theSpan">text<br></span>more</div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theDiv.focus();
+  sel.collapse(theDiv, 1);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-4.html

@@ -0,0 +1,28 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=bug1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #4 for bug1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><span id="theSpan">text<br></span>more</div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theSpan = document.getElementById("theSpan");
+  theDiv.focus();
+  sel.collapse(theSpan, 2);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-5-ref.html

@@ -0,0 +1,27 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #5 for bug 1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><span id="theSpan">text<br></span>    more</div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theDiv.focus();
+  sel.collapse(theDiv, 1);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/bug1263357-5.html

@@ -0,0 +1,28 @@
+<!DOCTYPE HTML><html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=bug1263357
+-->
+<head>
+    <meta charset="utf-8">
+    <title>Testcase #5 for bug1263357</title>
+    <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+    <script type="application/javascript" src="/tests/SimpleTest/EventUtils.js"></script>
+</head>
+<body>
+<div id="editable" contenteditable='true' spellcheck=false style="outline: 1px solid;"><span id="theSpan">text<br></span>    more</div>
+<script>
+
+function start() {
+  var sel = window.getSelection();
+  // Focus on editable block.
+  theDiv = document.getElementById("editable");
+  theSpan = document.getElementById("theSpan");
+  theDiv.focus();
+  sel.collapse(theSpan, 2);
+}
+
+SimpleTest.waitForFocus(start);
+
+</script>
+</body>
+</html>

layout/base/tests/mochitest.ini

@@ -173,6 +173,16 @@ support-files =
   bug1082486-1-ref.html
   bug1082486-2.html
   bug1082486-2-ref.html
+  bug1263357-1.html
+  bug1263357-1-ref.html
+  bug1263357-2.html
+  bug1263357-2-ref.html
+  bug1263357-3.html
+  bug1263357-3-ref.html
+  bug1263357-4.html
+  bug1263357-4-ref.html
+  bug1263357-5.html
+  bug1263357-5-ref.html
   input-maxlength-valid-before-change.html
   input-maxlength-valid-change.html
   input-maxlength-invalid-change.html

layout/base/tests/test_reftests_with_caret.html

@@ -181,6 +181,11 @@ var tests = [
     [ 'bug1259949-1.html' , 'bug1259949-1-ref.html'] ,
     [ 'bug1259949-2.html' , 'bug1259949-2-ref.html'] ,
     [ 'bug1263288.html'   , 'bug1263288-ref.html'] ,
+    [ 'bug1263357-1.html' , 'bug1263357-1-ref.html'] ,
+    [ 'bug1263357-2.html' , 'bug1263357-2-ref.html'] ,
+    [ 'bug1263357-3.html' , 'bug1263357-3-ref.html'] ,
+    [ 'bug1263357-4.html' , 'bug1263357-4-ref.html'] ,
+    [ 'bug1263357-5.html' , 'bug1263357-5-ref.html'] ,
     function() {SpecialPowers.pushPrefEnv({'clear': [['layout.accessiblecaret.enabled']]}, nextTest);} ,
 ];
 

layout/generic/nsSelection.cpp

@@ -1992,7 +1992,7 @@ nsFrameSelection::RepaintSelection(SelectionType aSelectionType)
 #endif
   return mDomSelections[index]->Repaint(mShell->GetPresContext());
 }
- 
+
 nsIFrame*
 nsFrameSelection::GetFrameForNodeOffset(nsIContent*        aNode,
                                         int32_t            aOffset,
@@ -2011,11 +2011,12 @@ nsFrameSelection::GetFrameForNodeOffset(nsIContent*        aNode,
   }
 
   nsIFrame* returnFrame = nullptr;
+  nsCOMPtr<nsIContent> theNode;
 
   while (true) {
     *aReturnOffset = aOffset;
 
-    nsCOMPtr<nsIContent> theNode = aNode;
+    theNode = aNode;
 
     if (aNode->IsElement()) {
       int32_t childIndex  = 0;
@@ -2135,6 +2136,18 @@ nsFrameSelection::GetFrameForNodeOffset(nsIContent*        aNode,
   if (!returnFrame)
     return nullptr;
 
+  // If we ended up here and were asked to position the caret after a visible
+  // break, let's return the frame on the next line instead if it exists.
+  if (aOffset > 0 &&  (uint32_t) aOffset >= aNode->Length() &&
+      theNode == aNode->GetLastChild()) {
+    nsIFrame* newFrame;
+    nsLayoutUtils::IsInvisibleBreak(theNode, &newFrame);
+    if (newFrame) {
+      returnFrame = newFrame;
+      *aReturnOffset = 0;
+    }
+  }
+
   // find the child frame containing the offset we want
   returnFrame->GetChildFrameContainingOffset(*aReturnOffset, aHint == CARET_ASSOCIATE_AFTER,
                                              &aOffset, &returnFrame);