Bug 1275528 part.4 IMMHandler should use insertion point relative query for getting character rect and caret rect r=m_kato

IMM always queries character rect or caret rect relative to insertion point.  Therefore, it makes sense to use the new feature, insertion point relative query content events for them.  Then, IMMHandler doesn't need to care mismatch between its cache and actual content information.

MozReview-Commit-ID: LCCrJkR77I8

--HG--
extra : rebase_source : c75f1b29e34e13df397de351909f07e2a95b6c5f

widget/windows/IMMHandler.cpp

@@ -2172,22 +2172,6 @@ IMMHandler::GetCharacterRectOfSelectedTextAt(nsWindow* aWindow,
     return false;
   }
 
-  // The base offset of aOffset is the start of composition string during
-  // composing or the start of selected string not during composing.
-  uint32_t baseOffset =
-    mIsComposing ? mCompositionStart : selection.mOffset;
-
-  CheckedInt<uint32_t> checkingOffset =
-    CheckedInt<uint32_t>(baseOffset) + aOffset;
-  if (NS_WARN_IF(!checkingOffset.isValid()) ||
-      checkingOffset.value() == UINT32_MAX) {
-    MOZ_LOG(gIMMLog, LogLevel::Error,
-      ("IMM: GetCharacterRectOfSelectedTextAt, FAILED, due to "
-       "aOffset is too large (aOffset=%u, baseOffset=%u, mIsComposing=%s)",
-       aOffset, baseOffset, GetBoolName(mIsComposing)));
-    return false;
-  }
-
   // If the offset is larger than the end of composition string or selected
   // string, we should return false since such case must be a bug of the caller
   // or the active IME.  If it's an IME's bug, we need to set targetLength to
@@ -2202,8 +2186,6 @@ IMMHandler::GetCharacterRectOfSelectedTextAt(nsWindow* aWindow,
     return false;
   }
 
-  uint32_t offset = checkingOffset.value();
-
   // If there is caret, we might be able to use caret rect.
   uint32_t caretOffset = UINT32_MAX;
   // There is a caret only when the normal selection is collapsed.
@@ -2213,24 +2195,26 @@ IMMHandler::GetCharacterRectOfSelectedTextAt(nsWindow* aWindow,
       // the composition string.
       if (mCursorPosition != NO_IME_CARET) {
         MOZ_ASSERT(mCursorPosition >= 0);
-        caretOffset = mCompositionStart + mCursorPosition;
+        caretOffset = mCursorPosition;
       } else if (!ShouldDrawCompositionStringOurselves() ||
                  mCompositionString.IsEmpty()) {
         // Otherwise, if there is no composition string, we should assume that
         // there is a caret at the start of composition string.
-        caretOffset = mCompositionStart;
+        caretOffset = 0;
       }
     } else {
       // If there is no composition, the selection offset is the caret offset.
-      caretOffset = selection.mOffset;
+      caretOffset = 0;
     }
   }
 
   // If there is a caret and retrieving offset is same as the caret offset,
   // we should use the caret rect.
-  if (offset != caretOffset) {
+  if (aOffset != caretOffset) {
     WidgetQueryContentEvent charRect(true, eQueryTextRect, aWindow);
-    charRect.InitForQueryTextRect(offset, 1);
+    WidgetQueryContentEvent::Options options;
+    options.mRelativeToInsertionPoint = true;
+    charRect.InitForQueryTextRect(aOffset, 1, options);
     aWindow->InitEvent(charRect, &point);
     DispatchEvent(aWindow, charRect);
     if (charRect.mSucceeded) {
@@ -2258,16 +2242,10 @@ IMMHandler::GetCaretRect(nsWindow* aWindow,
 {
   LayoutDeviceIntPoint point(0, 0);
 
-  Selection& selection = GetSelection();
-  if (!selection.EnsureValidSelection(aWindow)) {
-    MOZ_LOG(gIMMLog, LogLevel::Error,
-      ("IMM: GetCaretRect, FAILED, due to "
-       "Selection::EnsureValidSelection() failure"));
-    return false;
-  }
-
   WidgetQueryContentEvent caretRect(true, eQueryCaretRect, aWindow);
-  caretRect.InitForQueryCaretRect(selection.mOffset);
+  WidgetQueryContentEvent::Options options;
+  options.mRelativeToInsertionPoint = true;
+  caretRect.InitForQueryCaretRect(0, options);
   aWindow->InitEvent(caretRect, &point);
   DispatchEvent(aWindow, caretRect);
   if (!caretRect.mSucceeded) {