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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/WebPoint.h"
     37 #include "../platform/WebRect.h"
     38 #include "../platform/WebSize.h"
     39 #include "WebBeginFrameArgs.h"
     40 #include "WebCompositionUnderline.h"
     41 #include "WebTextDirection.h"
     42 #include "WebTextInputInfo.h"
     43 
     44 namespace blink {
     45 
     46 class WebCompositeAndReadbackAsyncCallback;
     47 class WebInputEvent;
     48 class WebLayerTreeView;
     49 class WebMouseEvent;
     50 class WebPagePopup;
     51 class WebString;
     52 class WebWidgetClient;
     53 struct WebPoint;
     54 struct WebRenderingStats;
     55 template <typename T> class WebVector;
     56 
     57 class WebWidget {
     58 public:
     59     // This method closes and deletes the WebWidget.
     60     virtual void close() { }
     61 
     62     // Returns the current size of the WebWidget.
     63     virtual WebSize size() { return WebSize(); }
     64 
     65     // Used to group a series of resize events. For example, if the user
     66     // drags a resizer then willStartLiveResize will be called, followed by a
     67     // sequence of resize events, ending with willEndLiveResize when the user
     68     // lets go of the resizer.
     69     virtual void willStartLiveResize() { }
     70 
     71     // Called to resize the WebWidget.
     72     virtual void resize(const WebSize&) { }
     73 
     74     // Resizes the unscaled pinch viewport. Normally the unscaled pinch
     75     // viewport is the same size as the main frame. The passed size becomes the
     76     // size of the viewport when unscaled (i.e. scale = 1). This is used to
     77     // shrink the visible viewport to allow things like the ChromeOS virtual
     78     // keyboard to overlay over content but allow scrolling it into view.
     79     virtual void resizePinchViewport(const WebSize&) { }
     80 
     81     // Ends a group of resize events that was started with a call to
     82     // willStartLiveResize.
     83     virtual void willEndLiveResize() { }
     84 
     85     // Called to notify the WebWidget of entering/exiting fullscreen mode. The
     86     // resize method may be called between will{Enter,Exit}FullScreen and
     87     // did{Enter,Exit}FullScreen.
     88     virtual void willEnterFullScreen() { }
     89     virtual void didEnterFullScreen() { }
     90     virtual void willExitFullScreen() { }
     91     virtual void didExitFullScreen() { }
     92 
     93     // Called to update imperative animation state. This should be called before
     94     // paint, although the client can rate-limit these calls.
     95     // FIXME: Remove this function once Chrome side patch lands.
     96     void animate(double monotonicFrameBeginTime)
     97     {
     98         beginFrame(WebBeginFrameArgs(monotonicFrameBeginTime));
     99     }
    100     virtual void beginFrame(const WebBeginFrameArgs& frameTime) { }
    101 
    102     // Called to notify that a previously begun frame was finished and
    103     // committed to the compositor. This is used to schedule lower priority
    104     // work after tasks such as input processing and painting.
    105     virtual void didCommitFrameToCompositor() { }
    106 
    107     // Called to layout the WebWidget. This MUST be called before Paint,
    108     // and it may result in calls to WebWidgetClient::didInvalidateRect.
    109     virtual void layout() { }
    110 
    111     // Called to paint the rectangular region within the WebWidget
    112     // onto the specified canvas at (viewPort.x,viewPort.y). You MUST call
    113     // Layout before calling this method. It is okay to call paint
    114     // multiple times once layout has been called, assuming no other
    115     // changes are made to the WebWidget (e.g., once events are
    116     // processed, it should be assumed that another call to layout is
    117     // warranted before painting again).
    118     virtual void paint(WebCanvas*, const WebRect& viewPort) { }
    119 
    120     virtual void paintCompositedDeprecated(WebCanvas*, const WebRect&) { }
    121 
    122     // The caller is responsible for keeping the WebCompositeAndReadbackAsyncCallback
    123     // object alive until it is called. This should only be called when
    124     // isAcceleratedCompositingActive() is true.
    125     virtual void compositeAndReadbackAsync(WebCompositeAndReadbackAsyncCallback*) { }
    126 
    127     // Returns true if we've started tracking repaint rectangles.
    128     virtual bool isTrackingRepaints() const { return false; }
    129 
    130     // Indicates that the compositing surface associated with this WebWidget is
    131     // ready to use.
    132     virtual void setCompositorSurfaceReady() { }
    133 
    134     // Called to inform the WebWidget of a change in theme.
    135     // Implementors that cache rendered copies of widgets need to re-render
    136     // on receiving this message
    137     virtual void themeChanged() { }
    138 
    139     // Called to inform the WebWidget of an input event. Returns true if
    140     // the event has been processed, false otherwise.
    141     virtual bool handleInputEvent(const WebInputEvent&) { return false; }
    142 
    143     // Called to inform the WebWidget of the mouse cursor's visibility.
    144     virtual void setCursorVisibilityState(bool isVisible) { }
    145 
    146     // Check whether the given point hits any registered touch event handlers.
    147     virtual bool hasTouchEventHandlersAt(const WebPoint&) { return true; }
    148 
    149     // Applies viewport related properties during a commit from the compositor
    150     // thread.
    151     virtual void applyViewportDeltas(
    152         const WebSize& scrollDelta,
    153         float scaleFactor,
    154         float topControlsDelta) { }
    155 
    156     // Applies viewport related properties during a commit from the compositor
    157     // thread.
    158     virtual void applyViewportDeltas(
    159         const WebSize& pinchViewportDelta,
    160         const WebSize& mainFrameDelta,
    161         float scaleFactor,
    162         float topControlsDelta) { }
    163 
    164     // Called to inform the WebWidget that mouse capture was lost.
    165     virtual void mouseCaptureLost() { }
    166 
    167     // Called to inform the WebWidget that it has gained or lost keyboard focus.
    168     virtual void setFocus(bool) { }
    169 
    170     // Called to inform the WebWidget of a new composition text.
    171     // If selectionStart and selectionEnd has the same value, then it indicates
    172     // the input caret position. If the text is empty, then the existing
    173     // composition text will be cancelled.
    174     // Returns true if the composition text was set successfully.
    175     virtual bool setComposition(
    176         const WebString& text,
    177         const WebVector<WebCompositionUnderline>& underlines,
    178         int selectionStart,
    179         int selectionEnd) { return false; }
    180 
    181     enum ConfirmCompositionBehavior {
    182         DoNotKeepSelection,
    183         KeepSelection,
    184     };
    185 
    186     // Called to inform the WebWidget to confirm an ongoing composition.
    187     // This method is same as confirmComposition(WebString());
    188     // Returns true if there is an ongoing composition.
    189     virtual bool confirmComposition() { return false; } // Deprecated
    190     virtual bool confirmComposition(ConfirmCompositionBehavior selectionBehavior) { return false; }
    191 
    192     // Called to inform the WebWidget to confirm an ongoing composition with a
    193     // new composition text. If the text is empty then the current composition
    194     // text is confirmed. If there is no ongoing composition, then deletes the
    195     // current selection and inserts the text. This method has no effect if
    196     // there is no ongoing composition and the text is empty.
    197     // Returns true if there is an ongoing composition or the text is inserted.
    198     virtual bool confirmComposition(const WebString& text) { return false; }
    199 
    200     // Fetches the character range of the current composition, also called the
    201     // "marked range." Returns true and fills the out-paramters on success;
    202     // returns false on failure.
    203     virtual bool compositionRange(size_t* location, size_t* length) { return false; }
    204 
    205     // Returns information about the current text input of this WebWidget.
    206     virtual WebTextInputInfo textInputInfo() { return WebTextInputInfo(); }
    207 
    208     // Returns the anchor and focus bounds of the current selection.
    209     // If the selection range is empty, it returns the caret bounds.
    210     virtual bool selectionBounds(WebRect& anchor, WebRect& focus) const { return false; }
    211 
    212     // Called to notify that IME candidate window has changed its visibility or
    213     // its appearance. These calls correspond to trigger
    214     // candidatewindow{show,update,hide} events defined in W3C IME API.
    215     virtual void didShowCandidateWindow() { }
    216     virtual void didUpdateCandidateWindow() { }
    217     virtual void didHideCandidateWindow() { }
    218 
    219     // Returns the text direction at the start and end bounds of the current selection.
    220     // If the selection range is empty, it returns false.
    221     virtual bool selectionTextDirection(WebTextDirection& start, WebTextDirection& end) const { return false; }
    222 
    223     // Returns true if the selection range is nonempty and its anchor is first
    224     // (i.e its anchor is its start).
    225     virtual bool isSelectionAnchorFirst() const { return false; }
    226 
    227     // Fetch the current selection range of this WebWidget. If there is no
    228     // selection, it will output a 0-length range with the location at the
    229     // caret. Returns true and fills the out-paramters on success; returns false
    230     // on failure.
    231     virtual bool caretOrSelectionRange(size_t* location, size_t* length) { return false; }
    232 
    233     // Changes the text direction of the selected input node.
    234     virtual void setTextDirection(WebTextDirection) { }
    235 
    236     // Returns true if the WebWidget uses GPU accelerated compositing
    237     // to render its contents.
    238     virtual bool isAcceleratedCompositingActive() const { return false; }
    239 
    240     // Returns true if the WebWidget created is of type WebPagePopup.
    241     virtual bool isPagePopup() const { return false; }
    242     // Returns true if the WebWidget created is of type WebPopupMenu.
    243     virtual bool isPopupMenu() const { return false; }
    244 
    245     // The WebLayerTreeView initialized on this WebWidgetClient will be going away and
    246     // is no longer safe to access.
    247     virtual void willCloseLayerTreeView() { }
    248 
    249     // Calling WebWidgetClient::requestPointerLock() will result in one
    250     // return call to didAcquirePointerLock() or didNotAcquirePointerLock().
    251     virtual void didAcquirePointerLock() { }
    252     virtual void didNotAcquirePointerLock() { }
    253 
    254     // Pointer lock was held, but has been lost. This may be due to a
    255     // request via WebWidgetClient::requestPointerUnlock(), or for other
    256     // reasons such as the user exiting lock, window focus changing, etc.
    257     virtual void didLosePointerLock() { }
    258 
    259     // Informs the WebWidget that the resizer rect changed. Happens for example
    260     // on mac, when a widget appears below the WebWidget without changing the
    261     // WebWidget's size (WebWidget::resize() automatically checks the resizer
    262     // rect.)
    263     virtual void didChangeWindowResizerRect() { }
    264 
    265     // The page background color. Can be used for filling in areas without
    266     // content.
    267     virtual WebColor backgroundColor() const { return 0xFFFFFFFF; /* SK_ColorWHITE */ }
    268 
    269     // The currently open page popup, which are calendar and datalist pickers
    270     // but not the select popup.
    271     virtual WebPagePopup* pagePopup() const { return 0; }
    272 
    273     // Sets the height subtracted from the Widget to accomodate the top controls.
    274     virtual void setTopControlsLayoutHeight(float) { }
    275 
    276 protected:
    277     ~WebWidget() { }
    278 };
    279 
    280 } // namespace blink
    281 
    282 #endif
    283