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      1 /*
      2  * Copyright (C) 2009 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef WebWidget_h
     32 #define WebWidget_h
     33 
     34 #include "../platform/WebCanvas.h"
     35 #include "../platform/WebCommon.h"
     36 #include "../platform/WebRect.h"
     37 #include "../platform/WebSize.h"
     38 #include "WebCompositionUnderline.h"
     39 #include "WebTextDirection.h"
     40 #include "WebTextInputInfo.h"
     41 
     42 namespace blink {
     43 
     44 class WebCompositeAndReadbackAsyncCallback;
     45 class WebInputEvent;
     46 class WebLayerTreeView;
     47 class WebMouseEvent;
     48 class WebString;
     49 struct WebPoint;
     50 struct WebRenderingStats;
     51 template <typename T> class WebVector;
     52 
     53 class WebWidget {
     54 public:
     55     // This method closes and deletes the WebWidget.
     56     virtual void close() { }
     57 
     58     // Returns the current size of the WebWidget.
     59     virtual WebSize size() { return WebSize(); }
     60 
     61     // Used to group a series of resize events. For example, if the user
     62     // drags a resizer then willStartLiveResize will be called, followed by a
     63     // sequence of resize events, ending with willEndLiveResize when the user
     64     // lets go of the resizer.
     65     virtual void willStartLiveResize() { }
     66 
     67     // Called to resize the WebWidget.
     68     virtual void resize(const WebSize&) { }
     69 
     70     // Resizes the unscaled pinch viewport. Normally the unscaled pinch
     71     // viewport is the same size as the main frame. The passed size becomes the
     72     // size of the viewport when unscaled (i.e. scale = 1). This is used to
     73     // shrink the visible viewport to allow things like the ChromeOS virtual
     74     // keyboard to overlay over content but allow scrolling it into view.
     75     virtual void resizePinchViewport(const WebSize&) { }
     76 
     77     // Ends a group of resize events that was started with a call to
     78     // willStartLiveResize.
     79     virtual void willEndLiveResize() { }
     80 
     81     // Called to notify the WebWidget of entering/exiting fullscreen mode. The
     82     // resize method may be called between will{Enter,Exit}FullScreen and
     83     // did{Enter,Exit}FullScreen.
     84     virtual void willEnterFullScreen() { }
     85     virtual void didEnterFullScreen() { }
     86     virtual void willExitFullScreen() { }
     87     virtual void didExitFullScreen() { }
     88 
     89     // Called to update imperative animation state. This should be called before
     90     // paint, although the client can rate-limit these calls.
     91     virtual void animate(double monotonicFrameBeginTime) { }
     92 
     93     // Called to layout the WebWidget. This MUST be called before Paint,
     94     // and it may result in calls to WebWidgetClient::didInvalidateRect.
     95     virtual void layout() { }
     96 
     97     // Called to paint the rectangular region within the WebWidget
     98     // onto the specified canvas at (viewPort.x,viewPort.y). You MUST call
     99     // Layout before calling this method. It is okay to call paint
    100     // multiple times once layout has been called, assuming no other
    101     // changes are made to the WebWidget (e.g., once events are
    102     // processed, it should be assumed that another call to layout is
    103     // warranted before painting again).
    104     virtual void paint(WebCanvas*, const WebRect& viewPort) { }
    105 
    106     virtual void paintCompositedDeprecated(WebCanvas*, const WebRect&) { }
    107 
    108     // The caller is responsible for keeping the WebCompositeAndReadbackAsyncCallback
    109     // object alive until it is called. This should only be called when
    110     // isAcceleratedCompositingActive() is true.
    111     virtual void compositeAndReadbackAsync(WebCompositeAndReadbackAsyncCallback*) { }
    112 
    113     // Returns true if we've started tracking repaint rectangles.
    114     virtual bool isTrackingRepaints() const { return false; }
    115 
    116     // Indicates that the compositing surface associated with this WebWidget is
    117     // ready to use.
    118     virtual void setCompositorSurfaceReady() { }
    119 
    120     // Called to inform the WebWidget of a change in theme.
    121     // Implementors that cache rendered copies of widgets need to re-render
    122     // on receiving this message
    123     virtual void themeChanged() { }
    124 
    125     // Called to inform the WebWidget of an input event. Returns true if
    126     // the event has been processed, false otherwise.
    127     virtual bool handleInputEvent(const WebInputEvent&) { return false; }
    128 
    129     // Called to inform the WebWidget of the mouse cursor's visibility.
    130     virtual void setCursorVisibilityState(bool isVisible) { }
    131 
    132     // Check whether the given point hits any registered touch event handlers.
    133     virtual bool hasTouchEventHandlersAt(const WebPoint&) { return true; }
    134 
    135     // Applies a scroll delta to the root layer, which is bundled with a page
    136     // scale factor that may apply a CSS transform on the whole document (used
    137     // for mobile-device pinch zooming). This is triggered by events sent to the
    138     // compositor thread.
    139     virtual void applyScrollAndScale(const WebSize& scrollDelta, float scaleFactor) { }
    140 
    141     // Called to inform the WebWidget that mouse capture was lost.
    142     virtual void mouseCaptureLost() { }
    143 
    144     // Called to inform the WebWidget that it has gained or lost keyboard focus.
    145     virtual void setFocus(bool) { }
    146 
    147     // Called to inform the WebWidget of a new composition text.
    148     // If selectionStart and selectionEnd has the same value, then it indicates
    149     // the input caret position. If the text is empty, then the existing
    150     // composition text will be cancelled.
    151     // Returns true if the composition text was set successfully.
    152     virtual bool setComposition(
    153         const WebString& text,
    154         const WebVector<WebCompositionUnderline>& underlines,
    155         int selectionStart,
    156         int selectionEnd) { return false; }
    157 
    158     enum ConfirmCompositionBehavior {
    159         DoNotKeepSelection,
    160         KeepSelection,
    161     };
    162 
    163     // Called to inform the WebWidget to confirm an ongoing composition.
    164     // This method is same as confirmComposition(WebString());
    165     // Returns true if there is an ongoing composition.
    166     virtual bool confirmComposition() { return false; } // Deprecated
    167     virtual bool confirmComposition(ConfirmCompositionBehavior selectionBehavior) { return false; }
    168 
    169     // Called to inform the WebWidget to confirm an ongoing composition with a
    170     // new composition text. If the text is empty then the current composition
    171     // text is confirmed. If there is no ongoing composition, then deletes the
    172     // current selection and inserts the text. This method has no effect if
    173     // there is no ongoing composition and the text is empty.
    174     // Returns true if there is an ongoing composition or the text is inserted.
    175     virtual bool confirmComposition(const WebString& text) { return false; }
    176 
    177     // Fetches the character range of the current composition, also called the
    178     // "marked range." Returns true and fills the out-paramters on success;
    179     // returns false on failure.
    180     virtual bool compositionRange(size_t* location, size_t* length) { return false; }
    181 
    182     // Returns information about the current text input of this WebWidget.
    183     virtual WebTextInputInfo textInputInfo() { return WebTextInputInfo(); }
    184 
    185     // Returns the anchor and focus bounds of the current selection.
    186     // If the selection range is empty, it returns the caret bounds.
    187     virtual bool selectionBounds(WebRect& anchor, WebRect& focus) const { return false; }
    188 
    189     // Called to notify that IME candidate window has changed its visibility or
    190     // its appearance. These calls correspond to trigger
    191     // candidatewindow{show,update,hide} events defined in W3C IME API.
    192     virtual void didShowCandidateWindow() { }
    193     virtual void didUpdateCandidateWindow() { }
    194     virtual void didHideCandidateWindow() { }
    195 
    196     // Returns the text direction at the start and end bounds of the current selection.
    197     // If the selection range is empty, it returns false.
    198     virtual bool selectionTextDirection(WebTextDirection& start, WebTextDirection& end) const { return false; }
    199 
    200     // Returns true if the selection range is nonempty and its anchor is first
    201     // (i.e its anchor is its start).
    202     virtual bool isSelectionAnchorFirst() const { return false; }
    203 
    204     // Fetch the current selection range of this WebWidget. If there is no
    205     // selection, it will output a 0-length range with the location at the
    206     // caret. Returns true and fills the out-paramters on success; returns false
    207     // on failure.
    208     virtual bool caretOrSelectionRange(size_t* location, size_t* length) { return false; }
    209 
    210     // Changes the text direction of the selected input node.
    211     virtual void setTextDirection(WebTextDirection) { }
    212 
    213     // Returns true if the WebWidget uses GPU accelerated compositing
    214     // to render its contents.
    215     virtual bool isAcceleratedCompositingActive() const { return false; }
    216 
    217     // Returns true if the WebWidget created is of type WebPagePopup.
    218     virtual bool isPagePopup() const { return false; }
    219     // Returns true if the WebWidget created is of type WebPopupMenu.
    220     virtual bool isPopupMenu() const { return false; }
    221 
    222     // The WebLayerTreeView initialized on this WebWidgetClient will be going away and
    223     // is no longer safe to access.
    224     virtual void willCloseLayerTreeView() { }
    225 
    226     // Calling WebWidgetClient::requestPointerLock() will result in one
    227     // return call to didAcquirePointerLock() or didNotAcquirePointerLock().
    228     virtual void didAcquirePointerLock() { }
    229     virtual void didNotAcquirePointerLock() { }
    230 
    231     // Pointer lock was held, but has been lost. This may be due to a
    232     // request via WebWidgetClient::requestPointerUnlock(), or for other
    233     // reasons such as the user exiting lock, window focus changing, etc.
    234     virtual void didLosePointerLock() { }
    235 
    236     // Informs the WebWidget that the resizer rect changed. Happens for example
    237     // on mac, when a widget appears below the WebWidget without changing the
    238     // WebWidget's size (WebWidget::resize() automatically checks the resizer
    239     // rect.)
    240     virtual void didChangeWindowResizerRect() { }
    241 
    242     // The page background color. Can be used for filling in areas without
    243     // content.
    244     virtual WebColor backgroundColor() const { return 0xFFFFFFFF; /* SK_ColorWHITE */ }
    245 
    246 protected:
    247     ~WebWidget() { }
    248 };
    249 
    250 } // namespace blink
    251 
    252 #endif
    253