popupmenuchromium.cpp

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

/*
 * Copyright (c) 2008, 2009, Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 * 
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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#include "config.h"
#include "PopupMenuChromium.h"

#include "CharacterNames.h"
#include "ChromeClientChromium.h"
#include "Font.h"
#include "FontSelector.h"
#include "FrameView.h"
#include "Frame.h"
#include "FramelessScrollView.h"
#include "FramelessScrollViewClient.h"
#include "GraphicsContext.h"
#include "IntRect.h"
#include "KeyboardCodes.h"
#include "Page.h"
#include "PlatformKeyboardEvent.h"
#include "PlatformMouseEvent.h"
#include "PlatformScreen.h"
#include "PlatformWheelEvent.h"
#include "PopupMenu.h"
#include "RenderTheme.h"
#include "ScrollbarTheme.h"
#include "SystemTime.h"

#include <wtf/CurrentTime.h>

using namespace WTF;
using namespace Unicode;

using std::min;
using std::max;

namespace WebCore {

typedef unsigned long long TimeStamp;

static const int kMaxVisibleRows = 20;
static const int kMaxHeight = 500;
static const int kBorderSize = 1;
static const TimeStamp kTypeAheadTimeoutMs = 1000;

// The settings used for the drop down menu.
// This is the delegate used if none is provided.
static const PopupContainerSettings dropDownSettings = {
    true, // focusOnShow
    true, // setTextOnIndexChange
    true, // acceptOnAbandon
    false // loopSelectionNavigation
};

// This class uses WebCore code to paint and handle events for a drop-down list
// box ("combobox" on Windows).
class PopupListBox : public FramelessScrollView, public RefCounted<PopupListBox> {
public:
    static PassRefPtr<PopupListBox> create(PopupMenuClient* client, const PopupContainerSettings& settings)
    {
        return adoptRef(new PopupListBox(client, settings));
    }

    // FramelessScrollView
    virtual void paint(GraphicsContext*, const IntRect&);
    virtual bool handleMouseDownEvent(const PlatformMouseEvent&);
    virtual bool handleMouseMoveEvent(const PlatformMouseEvent&);
    virtual bool handleMouseReleaseEvent(const PlatformMouseEvent&);
    virtual bool handleWheelEvent(const PlatformWheelEvent&);
    virtual bool handleKeyEvent(const PlatformKeyboardEvent&);

    // ScrollView
    virtual HostWindow* hostWindow() const;

    // PopupListBox methods

    // Shows the popup
    void showPopup();

    // Hides the popup.  Do not call this directly: use client->hidePopup().
    void hidePopup();

    // Updates our internal list to match the client.
    void updateFromElement();

    // Frees any allocated resources used in a particular popup session. 
    void clear();

    // Sets the index of the option that is displayed in the <select> widget in the page
    void setOriginalIndex(int index);

    // Gets the index of the item that the user is currently moused over or has selected with
    // the keyboard. This is not the same as the original index, since the user has not yet
    // accepted this input.
    int selectedIndex() const { return m_selectedIndex; }

    // Moves selection down/up the given number of items, scrolling if necessary.
    // Positive is down.  The resulting index will be clamped to the range
    // [0, numItems), and non-option items will be skipped.
    void adjustSelectedIndex(int delta);

    // Returns the number of items in the list.
    int numItems() const { return static_cast<int>(m_items.size()); }

    void setBaseWidth(int width) { m_baseWidth = width; }

    // Computes the size of widget and children.
    void layout();

    // Returns whether the popup wants to process events for the passed key.
    bool isInterestedInEventForKey(int keyCode);

private:
    friend class PopupContainer;
    friend class RefCounted<PopupListBox>;

    // A type of List Item
    enum ListItemType {
        TypeOption,
        TypeGroup,
        TypeSeparator
    };

    // A item (represented by <option> or <optgroup>) in the <select> widget. 
    struct ListItem {
        ListItem(const String& label, ListItemType type)
            : label(label.copy()), type(type), y(0) {}
        String label;
        ListItemType type;
        int y;  // y offset of this item, relative to the top of the popup.
    };

    PopupListBox(PopupMenuClient* client, const PopupContainerSettings& settings)
        : m_settings(settings)
        , m_originalIndex(0)
        , m_selectedIndex(0)
        , m_willAcceptOnAbandon(false)
        , m_visibleRows(0)
        , m_popupClient(client)
        , m_repeatingChar(0)
        , m_lastCharTime(0)
    {
        setScrollbarModes(ScrollbarAlwaysOff, ScrollbarAlwaysOff);
    }

    ~PopupListBox()
    {
        clear();
    }

    void disconnectClient() { m_popupClient = 0; }

    // Closes the popup
    void abandon();
    // Select an index in the list, scrolling if necessary.
    void selectIndex(int index);
    // Accepts the selected index as the value to be displayed in the <select> widget on
    // the web page, and closes the popup.
    void acceptIndex(int index);

    // Returns true if the selection can be changed to index.
    // Disabled items, or labels cannot be selected.
    bool isSelectableItem(int index);

    // Clears the selection (so no row appears selected).
    void clearSelection();

    // Scrolls to reveal the given index.
    void scrollToRevealRow(int index);
    void scrollToRevealSelection() { scrollToRevealRow(m_selectedIndex); }

    // Invalidates the row at the given index. 
    void invalidateRow(int index);

    // Gets the height of a row.
    int getRowHeight(int index);
    // Get the bounds of a row. 
    IntRect getRowBounds(int index);

    // Converts a point to an index of the row the point is over
    int pointToRowIndex(const IntPoint&);

    // Paint an individual row
    void paintRow(GraphicsContext*, const IntRect&, int rowIndex);

    // Test if the given point is within the bounds of the popup window.
    bool isPointInBounds(const IntPoint&);

    // Called when the user presses a text key.  Does a prefix-search of the items.
    void typeAheadFind(const PlatformKeyboardEvent&);

    // Returns the font to use for the given row
    Font getRowFont(int index);

    // Moves the selection down/up one item, taking care of looping back to the
    // first/last element if m_loopSelectionNavigation is true.
    void selectPreviousRow();
    void selectNextRow();

    // The settings that specify the behavior for this Popup window.
    PopupContainerSettings m_settings;

    // This is the index of the item marked as "selected" - i.e. displayed in the widget on the
    // page. 
    int m_originalIndex;

    // This is the index of the item that the user is hovered over or has selected using the 
    // keyboard in the list. They have not confirmed this selection by clicking or pressing 
    // enter yet however.
    int m_selectedIndex;

    // True if we should accept the selectedIndex as chosen, even if the popup
    // is "abandoned".  This is used for keyboard navigation, where we want the
    // selection to change immediately, and is only used if the settings
    // acceptOnAbandon field is true.
    bool m_willAcceptOnAbandon;

    // This is the number of rows visible in the popup. The maximum number visible at a time is
    // defined as being kMaxVisibleRows. For a scrolled popup, this can be thought of as the
    // page size in data units. 
    int m_visibleRows;

    // Our suggested width, not including scrollbar.
    int m_baseWidth;

    // A list of the options contained within the <select>
    Vector<ListItem*> m_items;

    // The <select> PopupMenuClient that opened us.
    PopupMenuClient* m_popupClient;

    // The scrollbar which has mouse capture.  Mouse events go straight to this
    // if non-NULL.
    RefPtr<Scrollbar> m_capturingScrollbar;

    // The last scrollbar that the mouse was over.  Used for mouseover highlights.
    RefPtr<Scrollbar> m_lastScrollbarUnderMouse;

    // The string the user has typed so far into the popup. Used for typeAheadFind.
    String m_typedString;

    // The char the user has hit repeatedly.  Used for typeAheadFind.
    UChar m_repeatingChar;

    // The last time the user hit a key.  Used for typeAheadFind.
    TimeStamp m_lastCharTime;
};

static PlatformMouseEvent constructRelativeMouseEvent(const PlatformMouseEvent& e,
                                                      FramelessScrollView* parent,
                                                      FramelessScrollView* child)
{
    IntPoint pos = parent->convertSelfToChild(child, e.pos());

    // FIXME: This is a horrible hack since PlatformMouseEvent has no setters for x/y.
    PlatformMouseEvent relativeEvent = e;
    IntPoint& relativePos = const_cast<IntPoint&>(relativeEvent.pos());
    relativePos.setX(pos.x());
    relativePos.setY(pos.y());
    return relativeEvent;
}

static PlatformWheelEvent constructRelativeWheelEvent(const PlatformWheelEvent& e,
                                                      FramelessScrollView* parent,
                                                      FramelessScrollView* child)
{
    IntPoint pos = parent->convertSelfToChild(child, e.pos());

    // FIXME: This is a horrible hack since PlatformWheelEvent has no setters for x/y.
    PlatformWheelEvent relativeEvent = e;
    IntPoint& relativePos = const_cast<IntPoint&>(relativeEvent.pos());
    relativePos.setX(pos.x());
    relativePos.setY(pos.y());
    return relativeEvent;
}

///////////////////////////////////////////////////////////////////////////////
// PopupContainer implementation

// static
PassRefPtr<PopupContainer> PopupContainer::create(PopupMenuClient* client,
                                                  const PopupContainerSettings& settings)
{
    return adoptRef(new PopupContainer(client, settings));
}

PopupContainer::PopupContainer(PopupMenuClient* client, const PopupContainerSettings& settings)
    : m_listBox(PopupListBox::create(client, settings))
    , m_settings(settings)
{
    setScrollbarModes(ScrollbarAlwaysOff, ScrollbarAlwaysOff);
}

PopupContainer::~PopupContainer()
{
    if (m_listBox)
        removeChild(m_listBox.get());
}

void PopupContainer::showPopup(FrameView* view)
{
    // Pre-layout, our size matches the <select> dropdown control.
    int selectHeight = frameRect().height();

    // Lay everything out to figure out our preferred size, then tell the view's
    // WidgetClient about it.  It should assign us a client.
    layout();

    ChromeClientChromium* chromeClient = static_cast<ChromeClientChromium*>(
        view->frame()->page()->chrome()->client());
    if (chromeClient) {
        // If the popup would extend past the bottom of the screen, open upwards
        // instead.
        FloatRect screen = screenAvailableRect(view);
        IntRect widgetRect = chromeClient->windowToScreen(frameRect());
        if (widgetRect.bottom() > static_cast<int>(screen.bottom()))
            widgetRect.move(0, -(widgetRect.height() + selectHeight));

        chromeClient->popupOpened(this, widgetRect, m_settings.focusOnShow);
    }

    if (!m_listBox->parent())
        addChild(m_listBox.get());

    // Enable scrollbars after the listbox is inserted into the hierarchy,
    // so it has a proper WidgetClient.
    m_listBox->setVerticalScrollbarMode(ScrollbarAuto);

    m_listBox->scrollToRevealSelection();

    invalidate();
}

void PopupContainer::hidePopup()
{
    if (client())
        client()->popupClosed(this);
}

void PopupContainer::layout()
{
    m_listBox->layout();

    // Place the listbox within our border.
    m_listBox->move(kBorderSize, kBorderSize);

    // Size ourselves to contain listbox + border.
    resize(m_listBox->width() + kBorderSize * 2, m_listBox->height() + kBorderSize * 2);

    invalidate();
}

bool PopupContainer::handleMouseDownEvent(const PlatformMouseEvent& event)