Bug 1130937 part.2 nsGtkIMModule should set candidiate window position to bottom left of the target clause in vertical writing mode r=m_kato

widget/TextEvents.h

@@ -410,6 +410,15 @@ public:
     return mRanges ? mRanges->TargetClauseOffset() : 0;
   }
 
+  uint32_t TargetClauseLength() const
+  {
+    uint32_t length = UINT32_MAX;
+    if (mRanges) {
+      length = mRanges->TargetClauseLength();
+    }
+    return length == UINT32_MAX ? mData.Length() : length;
+  }
+
   uint32_t RangeCount() const
   {
     return mRanges ? mRanges->Length() : 0;

widget/TextRange.h

@@ -195,6 +195,18 @@ class TextRangeArray final : public nsAutoTArray<TextRange, 10>
 
   NS_INLINE_DECL_REFCOUNTING(TextRangeArray)
 
+  const TextRange* GetTargetClause() const
+  {
+    for (uint32_t i = 0; i < Length(); ++i) {
+      const TextRange& range = ElementAt(i);
+      if (range.mRangeType == NS_TEXTRANGE_SELECTEDRAWTEXT ||
+          range.mRangeType == NS_TEXTRANGE_SELECTEDCONVERTEDTEXT) {
+        return &range;
+      }
+    }
+    return nullptr;
+  }
+
 public:
   bool IsComposing() const
   {
@@ -206,18 +218,20 @@ public:
     return false;
   }
 
-  // Returns target clase offset.  If there are selected clauses, this returns
+  // Returns target clause offset.  If there are selected clauses, this returns
   // the first selected clause offset.  Otherwise, 0.
   uint32_t TargetClauseOffset() const
   {
-    for (uint32_t i = 0; i < Length(); ++i) {
-      const TextRange& range = ElementAt(i);
-      if (range.mRangeType == NS_TEXTRANGE_SELECTEDRAWTEXT ||
-          range.mRangeType == NS_TEXTRANGE_SELECTEDCONVERTEDTEXT) {
-        return range.mStartOffset;
-      }
-    }
-    return 0;
+    const TextRange* range = GetTargetClause();
+    return range ? range->mStartOffset : 0;
+  }
+
+  // Returns target clause length.  If there are selected clauses, this returns
+  // the first selected clause length.  Otherwise, UINT32_MAX.
+  uint32_t TargetClauseLength() const
+  {
+    const TextRange* range = GetTargetClause();
+    return range ? range->Length() : UINT32_MAX;
   }
 
   bool Equals(const TextRangeArray& aOther) const

widget/gtk/nsGtkIMModule.cpp

@@ -14,6 +14,7 @@
 #include "mozilla/MiscEvents.h"
 #include "mozilla/Preferences.h"
 #include "mozilla/TextEvents.h"
+#include "WritingModes.h"
 
 using namespace mozilla;
 using namespace mozilla::widget;
@@ -111,7 +112,6 @@ nsGtkIMModule::nsGtkIMModule(nsWindow* aOwnerWindow)
     , mComposingContext(nullptr)
     , mCompositionStart(UINT32_MAX)
     , mProcessingKeyEvent(nullptr)
-    , mCompositionTargetOffset(UINT32_MAX)
     , mCompositionState(eCompositionState_NotComposing)
     , mIsIMFocused(false)
     , mIsDeletingSurrounding(false)
@@ -535,7 +535,7 @@ nsGtkIMModule::OnUpdateComposition()
         return;
     }
 
-    SetCursorPosition(GetActiveContext(), mCompositionTargetOffset);
+    SetCursorPosition(GetActiveContext());
 }
 
 void
@@ -819,7 +819,8 @@ nsGtkIMModule::OnStartCompositionNative(GtkIMContext *aContext)
     if (!DispatchCompositionStart(aContext)) {
         return;
     }
-    mCompositionTargetOffset = mCompositionStart;
+    mCompositionTargetRange.mOffset = mCompositionStart;
+    mCompositionTargetRange.mLength = 0;
 }
 
 /* static */
@@ -1195,7 +1196,9 @@ nsGtkIMModule::DispatchCompositionChangeEvent(
     // We cannot call SetCursorPosition for e10s-aware.
     // DispatchEvent is async on e10s, so composition rect isn't updated now
     // on tab parent.
-    mCompositionTargetOffset = targetOffset;
+    mCompositionTargetRange.mOffset = targetOffset;
+    mCompositionTargetRange.mLength =
+        compositionChangeEvent.mRanges->TargetClauseLength();
 
     return true;
 }
@@ -1238,7 +1241,7 @@ nsGtkIMModule::DispatchCompositionCommitEvent(
                                        NS_COMPOSITION_COMMIT_AS_IS;
     mCompositionState = eCompositionState_NotComposing;
     mCompositionStart = UINT32_MAX;
-    mCompositionTargetOffset = UINT32_MAX;
+    mCompositionTargetRange.Clear();
     mDispatchedCompositionString.Truncate();
 
     WidgetCompositionEvent compositionCommitEvent(true, message,
@@ -1393,16 +1396,19 @@ nsGtkIMModule::CreateTextRangeArray(GtkIMContext* aContext,
 }
 
 void
-nsGtkIMModule::SetCursorPosition(GtkIMContext* aContext,
-                                 uint32_t aTargetOffset)
+nsGtkIMModule::SetCursorPosition(GtkIMContext* aContext)
 {
     MOZ_LOG(gGtkIMLog, LogLevel::Info,
-        ("GtkIMModule(%p): SetCursorPosition, aContext=%p, aTargetOffset=%u",
-         this, aContext, aTargetOffset));
+        ("GtkIMModule(%p): SetCursorPosition, aContext=%p, "
+         "mCompositionTargetRange={ mOffset=%u, mLength=%u }"
+         "mSelection.mWritingMode=%s",
+         this, aContext, mCompositionTargetRange.mOffset,
+         mCompositionTargetRange.mLength,
+         GetWritingModeName(mSelection.mWritingMode).get()));
 
-    if (aTargetOffset == UINT32_MAX) {
+    if (!mCompositionTargetRange.IsValid()) {
         MOZ_LOG(gGtkIMLog, LogLevel::Info,
-            ("    FAILED, aTargetOffset is wrong offset"));
+            ("    FAILED, mCompositionTargetRange is invalid"));
         return;
     }
 
@@ -1420,7 +1426,15 @@ nsGtkIMModule::SetCursorPosition(GtkIMContext* aContext,
 
     WidgetQueryContentEvent charRect(true, NS_QUERY_TEXT_RECT,
                                      mLastFocusedWindow);
-    charRect.InitForQueryTextRect(aTargetOffset, 1);
+    if (mSelection.mWritingMode.IsVertical()) {
+        // For preventing the candidate window to overlap the target clause,
+        // we should set fake (typically, very tall) caret rect.
+        uint32_t length = mCompositionTargetRange.mLength ?
+            mCompositionTargetRange.mLength : 1;
+        charRect.InitForQueryTextRect(mCompositionTargetRange.mOffset, length);
+    } else {
+        charRect.InitForQueryTextRect(mCompositionTargetRange.mOffset, 1);
+    }
     InitEvent(charRect);
     nsEventStatus status;
     mLastFocusedWindow->DispatchEvent(&charRect, status);
@@ -1429,6 +1443,7 @@ nsGtkIMModule::SetCursorPosition(GtkIMContext* aContext,
             ("    FAILED, NS_QUERY_TEXT_RECT was failed"));
         return;
     }
+
     nsWindow* rootWindow =
         static_cast<nsWindow*>(mLastFocusedWindow->GetTopLevelWidget());
 

widget/gtk/nsGtkIMModule.h

@@ -125,8 +125,27 @@ protected:
     // event.
     GdkEventKey* mProcessingKeyEvent;
 
-    // current target offset of IME composition
-    uint32_t mCompositionTargetOffset;
+    struct Range
+    {
+        uint32_t mOffset;
+        uint32_t mLength;
+
+        Range()
+            : mOffset(UINT32_MAX)
+            , mLength(UINT32_MAX)
+        {
+        }
+
+        bool IsValid() const { return mOffset != UINT32_MAX; }
+        void Clear()
+        {
+            mOffset = UINT32_MAX;
+            mLength = UINT32_MAX;
+        }
+    };
+
+    // current target offset and length of IME composition
+    Range mCompositionTargetRange;
 
     // mCompositionState indicates current status of composition.
     enum eCompositionState {
@@ -327,14 +346,11 @@ protected:
                              const nsAString& aLastDispatchedData);
 
     /**
-     * Sets the offset's cursor position to IME.
+     * Move the candidate window with "fake" cursor position.
      *
      * @param aContext              A GtkIMContext which is being handled.
-     * @param aTargetOffset         Offset of a character which is anchor of
-     *                              a candidate window.  This is offset in
-     *                              UTF-16 string.
      */
-    void SetCursorPosition(GtkIMContext* aContext, uint32_t aTargetOffset);
+    void SetCursorPosition(GtkIMContext* aContext);
 
     // Queries the current selection offset of the window.
     uint32_t GetSelectionOffset(nsWindow* aWindow);