Bug 1435730 - part 1: Make TSFTextStore::GetTextExt() not return TS_E_NOLAYOUT error to Japanist 10 when the range is in composition string r=m_kato

Similar to ATOK, Japanist 10 requests all or part of composition string.
If we return TS_E_NOLAYOUT in this case, you'll see candidate window at
top-left of the screen.

For avoiding this issue, we should not return TS_E_NOLAYOUT to Japanist 10
when the query range is in composition string.

MozReview-Commit-ID: 2OPafUO5PQC

--HG--
extra : rebase_source : bd7a594d8d3540374d61860651b69528aa6e3793

modules/libpref/init/all.js

@@ -3965,11 +3965,16 @@ pref("intl.tsf.associate_imc_only_when_imm_ime_is_active", false);
 // Whether creates native caret for ATOK or not.
 pref("intl.tsf.hack.atok.create_native_caret", true);
 // Whether use available composition string rect for result of
-// ITfContextView::GetTextExt() even if the specified range is same as the
+// ITextStoreACP::GetTextExt() even if the specified range is same as the
 // range of composition string but some character rects of them are not
 // available.  Note that this is ignored if active ATOK is or older than 2016
 // and create_native_caret is true.
 pref("intl.tsf.hack.atok.do_not_return_no_layout_error_of_composition_string", true);
+// Whether use available composition string rect for result of
+// ITextStoreACP::GetTextExt() even if the specified range is same as or is in
+// the range of composition string but some character rects of them are not
+// available.
+pref("intl.tsf.hack.japanist10.do_not_return_no_layout_error_of_composition_string", true);
 // Whether use composition start position for the result of
 // ITfContextView::GetTextExt() if the specified range is larger than
 // composition start offset.

widget/windows/TSFTextStore.cpp

@@ -1096,6 +1096,7 @@ public:
   DECL_AND_IMPL_IS_TIP_ACTIVE(IsATOK2014Active)
   DECL_AND_IMPL_IS_TIP_ACTIVE(IsATOK2015Active)
   DECL_AND_IMPL_IS_TIP_ACTIVE(IsATOK2016Active)
+  DECL_AND_IMPL_IS_TIP_ACTIVE(IsJapanist10Active)
 
   DECL_AND_IMPL_IS_TIP_ACTIVE(IsMSBopomofoActive)
   DECL_AND_IMPL_IS_TIP_ACTIVE(IsMSChangJieActive)
@@ -1247,8 +1248,15 @@ private:
   // * ATOK Passport (confirmed with version 31.1.2)
   //   - {A38F2FD9-7199-45E1-841C-BE0313D8052F}
 
-  // * Japanist 10
-  //   - {E6D66705-1EDA-4373-8D01-1D0CB2D054C7}
+  bool IsJapanist10ActiveInternal() const
+  {
+    // {E6D66705-1EDA-4373-8D01-1D0CB2D054C7}
+    static const GUID kGUID = {
+      0xE6D66705, 0x1EDA, 0x4373,
+        { 0x8D, 0x01, 0x1D, 0x0C, 0xB2, 0xD0, 0x54, 0xC7 }
+    };
+    return mActiveTIPGUID == kGUID;
+  }
 
   /****************************************************************************
    * Traditional Chinese TIP
@@ -1705,6 +1713,10 @@ public:
   DECL_AND_IMPL_BOOL_PREF(
     "intl.tsf.hack.atok.do_not_return_no_layout_error_of_composition_string",
     DoNotReturnNoLayoutErrorToATOKOfCompositionString, true)
+  DECL_AND_IMPL_BOOL_PREF(
+    "intl.tsf.hack.japanist10."
+    "do_not_return_no_layout_error_of_composition_string",
+    DoNotReturnNoLayoutErrorToJapanist10OfCompositionString, true)
   DECL_AND_IMPL_BOOL_PREF(
     "intl.tsf.hack.ms_simplified_chinese.do_not_return_no_layout_error",
     DoNotReturnNoLayoutErrorToMSSimplifiedTIP, true)
@@ -3360,7 +3372,7 @@ TSFTextStore::SetSelectionInternal(const TS_SELECTION_ACP* pSelection,
   // Perhaps, we can ignore the difference change because it must not be
   // important for following edit.
   if (selectionForTSF.EqualsExceptDirection(*pSelection)) {
-    MOZ_LOG(sTextStoreLog, LogLevel::Error,
+    MOZ_LOG(sTextStoreLog, LogLevel::Warning,
       ("0x%p   TSFTextStore::SetSelectionInternal() Succeeded but "
        "did nothing because the selection range isn't changing", this));
     selectionForTSF.SetSelection(*pSelection);
@@ -4253,8 +4265,20 @@ TSFTextStore::GetTextExt(TsViewCookie vcView,
   MOZ_LOG(sTextStoreLog, LogLevel::Info,
     ("0x%p TSFTextStore::GetTextExt(vcView=%ld, "
      "acpStart=%ld, acpEnd=%ld, prc=0x%p, pfClipped=0x%p), "
+     "IsHandlingComposition()=%s, "
+     "mContentForTSF={ MinOffsetOfLayoutChanged()=%u, "
+     "LatestCompositionStartOffset()=%d, LatestCompositionEndOffset()=%d }, "
+     "mComposition= { IsComposing()=%s, mStart=%d, EndOffset()=%d }, "
      "mDeferNotifyingTSF=%s, mWaitingQueryLayout=%s",
      this, vcView, acpStart, acpEnd, prc, pfClipped,
+     GetBoolName(IsHandlingComposition()),
+     mContentForTSF.MinOffsetOfLayoutChanged(),
+     mContentForTSF.HasOrHadComposition() ?
+       mContentForTSF.LatestCompositionStartOffset() : -1,
+     mContentForTSF.HasOrHadComposition() ?
+       mContentForTSF.LatestCompositionEndOffset() : -1,
+     GetBoolName(mComposition.IsComposing()),
+     mComposition.mStart, mComposition.EndOffset(),
      GetBoolName(mDeferNotifyingTSF), GetBoolName(mWaitingQueryLayout)));
 
   if (!IsReadLocked()) {
@@ -4378,6 +4402,19 @@ TSFTextStore::GetTextExt(TsViewCookie vcView,
              mContentForTSF.LatestCompositionEndOffset() == acpEnd) {
       dontReturnNoLayoutError = true;
     }
+    // Japanist 10 fails to handle TS_E_NOLAYOUT when it decides the position of
+    // candidate window.  In such case, Japanist shows candidate window at
+    // top-left of the screen.  So, we should return the nearest caret rect
+    // where we know.
+    else if (
+      TSFPrefs::DoNotReturnNoLayoutErrorToJapanist10OfCompositionString() &&
+      TSFStaticSink::IsJapanist10Active() &&
+      acpStart >= mContentForTSF.LatestCompositionStartOffset() &&
+      acpStart <= mContentForTSF.LatestCompositionEndOffset() &&
+      acpEnd >= mContentForTSF.LatestCompositionStartOffset() &&
+      acpEnd <= mContentForTSF.LatestCompositionEndOffset()) {
+      dontReturnNoLayoutError = true;
+    }
     // Free ChangJie 2010 doesn't handle ITfContextView::GetTextExt() properly.
     // Prehaps, it's due to the bug of TSF.  We need to check if this is
     // necessary on Windows 10 before disabling this on Windows 10.