RenderTheme.h   [plain text]

/*
 * This file is part of the theme implementation for form controls in WebCore.
 *
 * Copyright (C) 2005 Apple Computer, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */

#ifndef RENDER_THEME_H
#define RENDER_THEME_H

#include "RenderObject.h"

namespace WebCore {
    
    class Element;
    class PopupMenu;
    class RenderMenuList;
    class RenderPopupMenu;
    
    enum ControlState { HoverState, PressedState, FocusState, EnabledState, CheckedState, ReadOnlyState };
    
    class RenderTheme {
public:
        RenderTheme() {}
        virtual ~RenderTheme() {}
        
        // This method is called whenever style has been computed for an element and the appearance
        // property has been set to a value other than "none".  The theme should map in all of the appropriate
        // metrics and defaults given the contents of the style.  This includes sophisticated operations like
        // selection of control size based off the font, the disabling of appearance when certain other properties like
        // "border" are set, or if the appearance is not supported by the theme.
        void adjustStyle(CSSStyleSelector*, RenderStyle*, Element*, 
                         bool UAHasAppearance, const BorderData&, const BackgroundLayer&, const Color& backgroundColor);
        
        // This method is called to paint the widget as a background of the RenderObject.  A widget's foreground, e.g., the
        // text of a button, is always rendered by the engine itself.  The boolean return value indicates
        // whether the CSS border/background should also be painted.
        bool paint(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r);
        bool paintBorderOnly(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r);
        bool paintDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r);
        
        // The remaining methods should be implemented by the platform-specific portion of the theme, e.g.,
        // RenderThemeMac.cpp for Mac OS X.
        
        // A method to obtain the baseline position for a "leaf" control.  This will only be used if a baseline
        // position cannot be determined by examining child content. Checkboxes and radio buttons are examples of
        // controls that need to do this.
        virtual short baselinePosition(const RenderObject* o) const;
        
        // A method for asking if a control is a container or not.  Leaf controls have to have some special behavior (like
        // the baseline position API above).
        virtual bool isControlContainer(EAppearance appearance) const;
        
        // A method asking if the control changes its tint when the window has focus or not.
        virtual bool controlSupportsTints(const RenderObject* o) const { return false; }
        
        // Whether or not the control has been styled enough by the author to disable the native appearance.
        virtual bool isControlStyled(const RenderStyle* style, const BorderData& border, 
                                     const BackgroundLayer& background, const Color& backgroundColor) const;
        
        // A general method asking if any control tinting is supported at all.
        virtual bool supportsControlTints() const { return false; }
        
        // Some controls may spill out of their containers (e.g., the check on an OS X checkbox).  When these controls repaint,
        // the theme needs to communicate this inflated rect to the engine so that it can invalidate the whole control.
        virtual void adjustRepaintRect(const RenderObject* o, IntRect& r) { }
        
        // This method is called whenever a relevant state changes on a particular themed object, e.g., the mouse becomes pressed
        // or a control becomes disabled.
        virtual bool stateChanged(RenderObject* o, ControlState state) const;
        
        // This method is called whenever the theme changes on the system in order to flush cached resources from the
        // old theme.
        virtual void themeChanged() {};
        
        // A method asking if the theme is able to draw the focus ring.
        virtual bool supportsFocusRing(const RenderStyle* style) const;
        
        // A method asking if the theme's controls actually care about redrawing when hovered.
        virtual bool supportsHover(const RenderStyle* style) const { return false; }
        
        // The selection color.
        Color activeSelectionBackgroundColor() const;
        Color inactiveSelectionBackgroundColor() const;
        
        // The platform selection color.
        virtual Color platformActiveSelectionBackgroundColor() const;
        virtual Color platformInactiveSelectionBackgroundColor() const;
        virtual Color platformActiveSelectionForegroundColor() const;
        virtual Color platformInactiveSelectionForegroundColor() const;
        
        // List Box selection color
        virtual Color activeListBoxSelectionBackgroundColor() const;
        virtual Color activeListBoxSelectionForegroundColor() const;
        virtual Color inactiveListBoxSelectionBackgroundColor() const;
        virtual Color inactiveListBoxSelectionForegroundColor() const;
        
        
        // System fonts.
        virtual int minimumMenuListSize(RenderStyle*) const { return 0; }
        
        virtual RenderPopupMenu* createPopupMenu(RenderArena*, Document*, RenderMenuList*) = 0;
        
        // Methods for state querying
        bool isChecked(const RenderObject* o) const;
        bool isIndeterminate(const RenderObject* o) const;
        bool isEnabled(const RenderObject* o) const;
        bool isFocused(const RenderObject* o) const;
        bool isPressed(const RenderObject* o) const;
        bool isHovered(const RenderObject* o) const;
        bool isReadOnlyControl(const RenderObject* o) const;
        
        virtual int popupInternalPaddingLeft(RenderStyle*) const { return 0; }
        virtual int popupInternalPaddingRight(RenderStyle*) const { return 0; }
        virtual int popupInternalPaddingTop(RenderStyle*) const { return 0; }
        virtual int popupInternalPaddingBottom(RenderStyle*) const { return 0; }
        
protected:
        
        // Methods for each appearance value.
        virtual void adjustCheckboxStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const;
        virtual bool paintCheckbox(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintCheckboxDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual void setCheckboxSize(RenderStyle* style) const {};
        
        virtual void adjustRadioStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const;
        virtual bool paintRadio(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintRadioDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual void setRadioSize(RenderStyle* style) const {};
        
        virtual void adjustButtonStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const;
        virtual bool paintButton(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintButtonDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintPushButtonDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintSquareButtonDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual void setButtonSize(RenderStyle* style) const {};
        
        virtual void adjustTextFieldStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const;
        virtual bool paintTextField(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintTextFieldDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        
        virtual void adjustTextAreaStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const;
        virtual bool paintTextArea(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintTextAreaDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        
        virtual void adjustMenuListStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const;
        virtual bool paintMenuList(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintMenuListDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        
        virtual void adjustMenuListButtonStyle(CSSStyleSelector* selector, RenderStyle* style, Element* e) const;
        virtual bool paintMenuListButton(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
        virtual bool paintMenuListButtonDecorations(RenderObject* o, const RenderObject::PaintInfo& i, const IntRect& r) { return true; }
    };
    
    // Function to obtain the theme.  This is implemented in your platform-specific theme implementation to hand
    // back the appropriate platform theme.
    RenderTheme* theme();
    
}

#endif