1 files changed, 490 insertions, 0 deletions
diff --git a/dom/events/TextComposition.h b/dom/events/TextComposition.h
new file mode 100644
index 000000000..a4161f82f
--- /dev/null
+++ b/dom/events/TextComposition.h
@@ -0,0 +1,490 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_TextComposition_h
+#define mozilla_TextComposition_h
+
+#include "nsCOMPtr.h"
+#include "nsINode.h"
+#include "nsIWeakReference.h"
+#include "nsIWidget.h"
+#include "nsTArray.h"
+#include "nsThreadUtils.h"
+#include "nsPresContext.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/EventForwards.h"
+#include "mozilla/TextRange.h"
+#include "mozilla/dom/TabParent.h"
+
+class nsIEditor;
+
+namespace mozilla {
+
+class EventDispatchingCallback;
+class IMEStateManager;
+
+/**
+ * TextComposition represents a text composition.  This class stores the
+ * composition event target and its presContext.  At dispatching the event via
+ * this class, the instances use the stored event target.
+ */
+
+class TextComposition final
+{
+  friend class IMEStateManager;
+
+  NS_INLINE_DECL_REFCOUNTING(TextComposition)
+
+public:
+  typedef dom::TabParent TabParent;
+
+  static bool IsHandlingSelectionEvent() { return sHandlingSelectionEvent; }
+
+  TextComposition(nsPresContext* aPresContext,
+                  nsINode* aNode,
+                  TabParent* aTabParent,
+                  WidgetCompositionEvent* aCompositionEvent);
+
+  bool Destroyed() const { return !mPresContext; }
+  nsPresContext* GetPresContext() const { return mPresContext; }
+  nsINode* GetEventTargetNode() const { return mNode; }
+  // The latest CompositionEvent.data value except compositionstart event.
+  // This value is modified at dispatching compositionupdate.
+  const nsString& LastData() const { return mLastData; }
+  // The composition string which is already handled by the focused editor.
+  // I.e., this value must be same as the composition string on the focused
+  // editor.  This value is modified at a call of
+  // EditorDidHandleCompositionChangeEvent().
+  // Note that mString and mLastData are different between dispatcing
+  // compositionupdate and compositionchange event handled by focused editor.
+  const nsString& String() const { return mString; }
+  // The latest clauses range of the composition string.
+  // During compositionupdate event, GetRanges() returns old ranges.
+  // So if getting on compositionupdate, Use GetLastRange instead of GetRange().
+  TextRangeArray* GetLastRanges() const { return mLastRanges; }
+  // Returns the clauses and/or caret range of the composition string.
+  // This is modified at a call of EditorWillHandleCompositionChangeEvent().
+  // This may return null if there is no clauses and caret.
+  // XXX We should return |const TextRangeArray*| here, but it causes compile
+  //     error due to inaccessible Release() method.
+  TextRangeArray* GetRanges() const { return mRanges; }
+  // Returns the widget which is proper to call NotifyIME().
+  nsIWidget* GetWidget() const
+  {
+    return mPresContext ? mPresContext->GetRootWidget() : nullptr;
+  }
+  // Returns true if the composition is started with synthesized event which
+  // came from nsDOMWindowUtils.
+  bool IsSynthesizedForTests() const { return mIsSynthesizedForTests; }
+
+  const widget::NativeIMEContext& GetNativeIMEContext() const
+  {
+    return mNativeContext;
+  }
+
+  /**
+   * This is called when IMEStateManager stops managing the instance.
+   */
+  void Destroy();
+
+  /**
+   * Request to commit (or cancel) the composition to IME.  This method should
+   * be called only by IMEStateManager::NotifyIME().
+   */
+  nsresult RequestToCommit(nsIWidget* aWidget, bool aDiscard);
+
+  /**
+   * Send a notification to IME.  It depends on the IME or platform spec what
+   * will occur (or not occur).
+   */
+  nsresult NotifyIME(widget::IMEMessage aMessage);
+
+  /**
+   * the offset of first composition string
+   */
+  uint32_t NativeOffsetOfStartComposition() const
+  {
+    return mCompositionStartOffset;
+  }
+
+  /**
+   * the offset of first selected clause or start of composition
+   */
+  uint32_t NativeOffsetOfTargetClause() const
+  {
+    return mCompositionStartOffset + mTargetClauseOffsetInComposition;
+  }
+
+  /**
+   * Returns true if there is non-empty composition string and it's not fixed.
+   * Otherwise, false.
+   */
+  bool IsComposing() const { return mIsComposing; }
+
+  /**
+   * Returns true while editor is handling an event which is modifying the
+   * composition string.
+   */
+  bool IsEditorHandlingEvent() const
+  {
+    return mIsEditorHandlingEvent;
+  }
+
+  /**
+   * StartHandlingComposition() and EndHandlingComposition() are called by
+   * editor when it holds a TextComposition instance and release it.
+   */
+  void StartHandlingComposition(nsIEditor* aEditor);
+  void EndHandlingComposition(nsIEditor* aEditor);
+
+  /**
+   * OnEditorDestroyed() is called when the editor is destroyed but there is
+   * active composition.
+   */
+  void OnEditorDestroyed();
+
+  /**
+   * CompositionChangeEventHandlingMarker class should be created at starting
+   * to handle text event in focused editor.  This calls
+   * EditorWillHandleCompositionChangeEvent() and
+   * EditorDidHandleCompositionChangeEvent() automatically.
+   */
+  class MOZ_STACK_CLASS CompositionChangeEventHandlingMarker
+  {
+  public:
+    CompositionChangeEventHandlingMarker(
+      TextComposition* aComposition,
+      const WidgetCompositionEvent* aCompositionChangeEvent)
+      : mComposition(aComposition)
+    {
+      mComposition->EditorWillHandleCompositionChangeEvent(
+                      aCompositionChangeEvent);
+    }
+
+    ~CompositionChangeEventHandlingMarker()
+    {
+      mComposition->EditorDidHandleCompositionChangeEvent();
+    }
+
+  private:
+    RefPtr<TextComposition> mComposition;
+    CompositionChangeEventHandlingMarker();
+    CompositionChangeEventHandlingMarker(
+      const CompositionChangeEventHandlingMarker& aOther);
+  };
+
+private:
+  // Private destructor, to discourage deletion outside of Release():
+  ~TextComposition()
+  {
+    // WARNING: mPresContext may be destroying, so, be careful if you touch it.
+  }
+
+  // sHandlingSelectionEvent is true while TextComposition sends a selection
+  // event to ContentEventHandler.
+  static bool sHandlingSelectionEvent;
+
+  // This class holds nsPresContext weak.  This instance shouldn't block
+  // destroying it.  When the presContext is being destroyed, it's notified to
+  // IMEStateManager::OnDestroyPresContext(), and then, it destroy
+  // this instance.
+  nsPresContext* mPresContext;
+  nsCOMPtr<nsINode> mNode;
+  RefPtr<TabParent> mTabParent;
+
+  // This is the clause and caret range information which is managed by
+  // the focused editor.  This may be null if there is no clauses or caret.
+  RefPtr<TextRangeArray> mRanges;
+  // Same as mRange, but mRange will have old data during compositionupdate.
+  // So this will be valied during compositionupdate.
+  RefPtr<TextRangeArray> mLastRanges;
+
+  // mNativeContext stores a opaque pointer.  This works as the "ID" for this
+  // composition.  Don't access the instance, it may not be available.
+  widget::NativeIMEContext mNativeContext;
+
+  // mEditorWeak is a weak reference to the focused editor handling composition.
+  nsWeakPtr mEditorWeak;
+
+  // mLastData stores the data attribute of the latest composition event (except
+  // the compositionstart event).
+  nsString mLastData;
+
+  // mString stores the composition text which has been handled by the focused
+  // editor.
+  nsString mString;
+
+  // Offset of the composition string from start of the editor
+  uint32_t mCompositionStartOffset;
+  // Offset of the selected clause of the composition string from
+  // mCompositionStartOffset
+  uint32_t mTargetClauseOffsetInComposition;
+
+  // See the comment for IsSynthesizedForTests().
+  bool mIsSynthesizedForTests;
+
+  // See the comment for IsComposing().
+  bool mIsComposing;
+
+  // mIsEditorHandlingEvent is true while editor is modifying the composition
+  // string.
+  bool mIsEditorHandlingEvent;
+
+  // mIsRequestingCommit or mIsRequestingCancel is true *only* while we're
+  // requesting commit or canceling the composition.  In other words, while
+  // one of these values is true, we're handling the request.
+  bool mIsRequestingCommit;
+  bool mIsRequestingCancel;
+
+  // mRequestedToCommitOrCancel is true *after* we requested IME to commit or
+  // cancel the composition.  In other words, we already requested of IME that
+  // it commits or cancels current composition.
+  // NOTE: Before this is set true, both mIsRequestingCommit and
+  //       mIsRequestingCancel are set false.
+  bool mRequestedToCommitOrCancel;
+
+  // mWasNativeCompositionEndEventDiscarded is true if this composition was
+  // requested commit or cancel itself but native compositionend event is
+  // discarded by PresShell due to not safe to dispatch events.
+  bool mWasNativeCompositionEndEventDiscarded;
+
+  // Allow control characters appear in composition string.
+  // When this is false, control characters except
+  // CHARACTER TABULATION (horizontal tab) are removed from
+  // both composition string and data attribute of compositionupdate
+  // and compositionend events.
+  bool mAllowControlCharacters;
+
+  // mWasCompositionStringEmpty is true if the composition string was empty
+  // when DispatchCompositionEvent() is called.
+  bool mWasCompositionStringEmpty;
+
+  // Hide the default constructor and copy constructor.
+  TextComposition()
+    : mPresContext(nullptr)
+    , mNativeContext(nullptr)
+    , mCompositionStartOffset(0)
+    , mTargetClauseOffsetInComposition(0)
+    , mIsSynthesizedForTests(false)
+    , mIsComposing(false)
+    , mIsEditorHandlingEvent(false)
+    , mIsRequestingCommit(false)
+    , mIsRequestingCancel(false)
+    , mRequestedToCommitOrCancel(false)
+    , mWasNativeCompositionEndEventDiscarded(false)
+    , mAllowControlCharacters(false)
+    , mWasCompositionStringEmpty(true)
+  {}
+  TextComposition(const TextComposition& aOther);
+
+  /**
+   * GetEditor() returns nsIEditor pointer of mEditorWeak.
+   */
+  already_AddRefed<nsIEditor> GetEditor() const;
+
+  /**
+   * HasEditor() returns true if mEditorWeak holds nsIEditor instance which is
+   * alive.  Otherwise, false.
+   */
+  bool HasEditor() const;
+
+  /**
+   * EditorWillHandleCompositionChangeEvent() must be called before the focused
+   * editor handles the compositionchange event.
+   */
+  void EditorWillHandleCompositionChangeEvent(
+         const WidgetCompositionEvent* aCompositionChangeEvent);
+
+  /**
+   * EditorDidHandleCompositionChangeEvent() must be called after the focused
+   * editor handles a compositionchange event.
+   */
+  void EditorDidHandleCompositionChangeEvent();
+
+  /**
+   * IsValidStateForComposition() returns true if it's safe to dispatch an event
+   * to the DOM tree.  Otherwise, false.
+   * WARNING: This doesn't check script blocker state.  It should be checked
+   *          before dispatching the first event.
+   */
+  bool IsValidStateForComposition(nsIWidget* aWidget) const;
+
+  /**
+   * DispatchCompositionEvent() dispatches the aCompositionEvent to the mContent
+   * synchronously. The caller must ensure that it's safe to dispatch the event.
+   */
+  void DispatchCompositionEvent(WidgetCompositionEvent* aCompositionEvent,
+                                nsEventStatus* aStatus,
+                                EventDispatchingCallback* aCallBack,
+                                bool aIsSynthesized);
+
+  /**
+   * Simply calling EventDispatcher::Dispatch() with plugin event.
+   * If dispatching event has no orginal clone, aOriginalEvent can be null.
+   */
+  void DispatchEvent(WidgetCompositionEvent* aDispatchEvent,
+                     nsEventStatus* aStatus,
+                     EventDispatchingCallback* aCallback,
+                     const WidgetCompositionEvent *aOriginalEvent = nullptr);
+
+  /**
+   * HandleSelectionEvent() sends the selection event to ContentEventHandler
+   * or dispatches it to the focused child process.
+   */
+  void HandleSelectionEvent(WidgetSelectionEvent* aSelectionEvent)
+  {
+    HandleSelectionEvent(mPresContext, mTabParent, aSelectionEvent);
+  }
+  static void HandleSelectionEvent(nsPresContext* aPresContext,
+                                   TabParent* aTabParent,
+                                   WidgetSelectionEvent* aSelectionEvent);
+
+  /**
+   * MaybeDispatchCompositionUpdate() may dispatch a compositionupdate event
+   * if aCompositionEvent changes composition string.
+   * @return Returns false if dispatching the compositionupdate event caused
+   *         destroying this composition.
+   */
+  bool MaybeDispatchCompositionUpdate(
+         const WidgetCompositionEvent* aCompositionEvent);
+
+  /**
+   * CloneAndDispatchAs() dispatches a composition event which is
+   * duplicateed from aCompositionEvent and set the aMessage.
+   *
+   * @return Returns BaseEventFlags which is the result of dispatched event.
+   */
+  BaseEventFlags CloneAndDispatchAs(
+                   const WidgetCompositionEvent* aCompositionEvent,
+                   EventMessage aMessage,
+                   nsEventStatus* aStatus = nullptr,
+                   EventDispatchingCallback* aCallBack = nullptr);
+
+  /**
+   * If IME has already dispatched compositionend event but it was discarded
+   * by PresShell due to not safe to dispatch, this returns true.
+   */
+  bool WasNativeCompositionEndEventDiscarded() const
+  {
+    return mWasNativeCompositionEndEventDiscarded;
+  }
+
+  /**
+   * OnCompositionEventDiscarded() is called when PresShell discards
+   * compositionupdate, compositionend or compositionchange event due to not
+   * safe to dispatch event.
+   */
+  void OnCompositionEventDiscarded(WidgetCompositionEvent* aCompositionEvent);
+
+  /**
+   * OnCompositionEventDispatched() is called after a composition event is
+   * dispatched.
+   */
+  void OnCompositionEventDispatched(
+         const WidgetCompositionEvent* aDispatchEvent);
+
+  /**
+   * MaybeNotifyIMEOfCompositionEventHandled() notifies IME of composition
+   * event handled.  This should be called after dispatching a composition
+   * event which came from widget.
+   */
+  void MaybeNotifyIMEOfCompositionEventHandled(
+         const WidgetCompositionEvent* aCompositionEvent);
+
+  /**
+   * GetSelectionStartOffset() returns normal selection start offset in the
+   * editor which has this composition.
+   * If it failed or lost focus, this would return 0.
+   */
+  uint32_t GetSelectionStartOffset();
+
+  /**
+   * OnStartOffsetUpdatedInChild() is called when composition start offset
+   * is updated in the child process.  I.e., this is called and never called
+   * if the composition is in this process.
+   * @param aStartOffset        New composition start offset with native
+   *                            linebreaks.
+   */
+  void OnStartOffsetUpdatedInChild(uint32_t aStartOffset);
+
+  /**
+   * CompositionEventDispatcher dispatches the specified composition (or text)
+   * event.
+   */
+  class CompositionEventDispatcher : public Runnable
+  {
+  public:
+    CompositionEventDispatcher(TextComposition* aTextComposition,
+                               nsINode* aEventTarget,
+                               EventMessage aEventMessage,
+                               const nsAString& aData,
+                               bool aIsSynthesizedEvent = false);
+    NS_IMETHOD Run() override;
+
+  private:
+    RefPtr<TextComposition> mTextComposition;
+    nsCOMPtr<nsINode> mEventTarget;
+    nsString mData;
+    EventMessage mEventMessage;
+    bool mIsSynthesizedEvent;
+
+    CompositionEventDispatcher() : mIsSynthesizedEvent(false) {};
+  };
+
+  /**
+   * DispatchCompositionEventRunnable() dispatches a composition event to the
+   * content.  Be aware, if you use this method, nsPresShellEventCB isn't used.
+   * That means that nsIFrame::HandleEvent() is never called.
+   * WARNING: The instance which is managed by IMEStateManager may be
+   *          destroyed by this method call.
+   *
+   * @param aEventMessage       Must be one of composition events.
+   * @param aData               Used for mData value.
+   * @param aIsSynthesizingCommit   true if this is called for synthesizing
+   *                                commit or cancel composition.  Otherwise,
+   *                                false.
+   */
+  void DispatchCompositionEventRunnable(EventMessage aEventMessage,
+                                        const nsAString& aData,
+                                        bool aIsSynthesizingCommit = false);
+};
+
+/**
+ * TextCompositionArray manages the instances of TextComposition class.
+ * Managing with array is enough because only one composition is typically
+ * there.  Even if user switches native IME context, it's very rare that
+ * second or more composition is started.
+ * It's assumed that this is used by IMEStateManager for storing all active
+ * compositions in the process.  If the instance is it, each TextComposition
+ * in the array can be destroyed by calling some methods of itself.
+ */
+
+class TextCompositionArray final :
+  public AutoTArray<RefPtr<TextComposition>, 2>
+{
+public:
+  // Looking for per native IME context.
+  index_type IndexOf(const widget::NativeIMEContext& aNativeIMEContext);
+  index_type IndexOf(nsIWidget* aWidget);
+
+  TextComposition* GetCompositionFor(nsIWidget* aWidget);
+  TextComposition* GetCompositionFor(
+                     const WidgetCompositionEvent* aCompositionEvent);
+
+  // Looking for per nsPresContext
+  index_type IndexOf(nsPresContext* aPresContext);
+  index_type IndexOf(nsPresContext* aPresContext, nsINode* aNode);
+
+  TextComposition* GetCompositionFor(nsPresContext* aPresContext);
+  TextComposition* GetCompositionFor(nsPresContext* aPresContext,
+                                     nsINode* aNode);
+  TextComposition* GetCompositionInContent(nsPresContext* aPresContext,
+                                           nsIContent* aContent);
+};
+
+} // namespace mozilla
+
+#endif // #ifndef mozilla_TextComposition_h