gfx/public/nsITheme.h

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  38
  39 /* service providing platform-specific native rendering for widgets */
  40
  41 #ifndef nsITheme_h_
  42 #define nsITheme_h_
  43
  44 #include "nsISupports.h"
  45 #include "nsCOMPtr.h"
  46 #include "nsColor.h"
  47
  48 struct nsRect;
  49 struct nsIntSize;
  50 struct nsFont;
  51 struct nsIntMargin;
  52 class nsPresContext;
  53 class nsIRenderingContext;
  54 class nsIDeviceContext;
  55 class nsIFrame;
  56 class nsIContent;
  57 class nsIAtom;
  58
  59 // IID for the nsITheme interface
  60 // {887e8902-db6b-41b4-8481-a80f49c5a93a}
  61  #define NS_ITHEME_IID     \
  62 { 0x887e8902, 0xdb6b, 0x41b4, { 0x84, 0x81, 0xa8, 0x0f, 0x49, 0xc5, 0xa9, 0x3a } }
  63
  64 // {D930E29B-6909-44e5-AB4B-AF10D6923705}
  65 #define NS_THEMERENDERER_CID \
  66 { 0xd930e29b, 0x6909, 0x44e5, { 0xab, 0x4b, 0xaf, 0x10, 0xd6, 0x92, 0x37, 0x5 } }
  67
  68 enum nsTransparencyMode {
  69   eTransparencyOpaque = 0,  // Fully opaque
  70   eTransparencyTransparent, // Parts of the window may be transparent
  71   eTransparencyGlass        // Transparent parts of the window have Vista AeroGlass effect applied
  72 };
  73
  74 /**
  75  * nsITheme is a service that provides platform-specific native
  76  * rendering for widgets.  In other words, it provides the necessary
  77  * operations to draw a rendering object (an nsIFrame) as a native
  78  * widget.
  79  *
  80  * All the methods on nsITheme take a rendering context or device
  81  * context, a frame (the rendering object), and a widget type (one of
  82  * the constants in nsThemeConstants.h).
  83  */
  84 class nsITheme: public nsISupports {
  85 public:
  86   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ITHEME_IID)
  87
  88   NS_IMETHOD DrawWidgetBackground(nsIRenderingContext* aContext,
  89                                   nsIFrame* aFrame,
  90                                   PRUint8 aWidgetType,
  91                                   const nsRect& aRect,
  92                                   const nsRect& aDirtyRect)=0;
  93
  94   /**
  95    * Get the computed CSS border for the widget, in pixels.
  96    */
  97   NS_IMETHOD GetWidgetBorder(nsIDeviceContext* aContext,
  98                              nsIFrame* aFrame,
  99                              PRUint8 aWidgetType,
 100                              nsIntMargin* aResult)=0;
 101
 102   /**
 103    * This method can return PR_FALSE to indicate that the CSS padding
 104    * value should be used.  Otherwise, it will fill in aResult with the
 105    * computed padding, in pixels, and return PR_TRUE.
 106    *
 107    * XXXldb This ought to be required to return true for non-containers
 108    * so that we don't let specified padding that has no effect change
 109    * the computed padding and potentially the size.
 110    */
 111   virtual PRBool GetWidgetPadding(nsIDeviceContext* aContext,
 112                                   nsIFrame* aFrame,
 113                                   PRUint8 aWidgetType,
 114                                   nsIntMargin* aResult) = 0;
 115
 116   /**
 117    * On entry, *aResult is positioned at 0,0 and sized to the new size
 118    * of aFrame (aFrame->GetSize() may be stale and should not be used).
 119    * This method can return PR_FALSE to indicate that no special
 120    * overflow area is required by the native widget. Otherwise it will
 121    * fill in aResult with the desired overflow area, in appunits, relative
 122    * to the frame origin, and return PR_TRUE.
 123    */
 124   virtual PRBool GetWidgetOverflow(nsIDeviceContext* aContext,
 125                                    nsIFrame* aFrame,
 126                                    PRUint8 aWidgetType,
 127                                    /*INOUT*/ nsRect* aOverflowRect)
 128   { return PR_FALSE; }
 129
 130   /**
 131    * Get the minimum border-box size of a widget, in *pixels* (in
 132    * |aResult|).  If |aIsOverridable| is set to true, this size is a
 133    * minimum size; if false, this size is the only valid size for the
 134    * widget.
 135    */
 136   NS_IMETHOD GetMinimumWidgetSize(nsIRenderingContext* aContext,
 137                                   nsIFrame* aFrame,
 138                                   PRUint8 aWidgetType,
 139                                   nsIntSize* aResult,
 140                                   PRBool* aIsOverridable)=0;
 141
 142   virtual nsTransparencyMode GetWidgetTransparency(PRUint8 aWidgetType)=0;
 143
 144   NS_IMETHOD WidgetStateChanged(nsIFrame* aFrame, PRUint8 aWidgetType,
 145                                 nsIAtom* aAttribute, PRBool* aShouldRepaint)=0;
 146
 147   NS_IMETHOD ThemeChanged()=0;
 148
 149   /**
 150    * Can the nsITheme implementation handle this widget?
 151    */
 152   virtual PRBool ThemeSupportsWidget(nsPresContext* aPresContext,
 153                                      nsIFrame* aFrame,
 154                                      PRUint8 aWidgetType)=0;
 155
 156   virtual PRBool WidgetIsContainer(PRUint8 aWidgetType)=0;
 157
 158   /**
 159    * Does the nsITheme implementation draw its own focus ring for this widget?
 160    */
 161   virtual PRBool ThemeDrawsFocusForWidget(nsPresContext* aPresContext,
 162                                           nsIFrame* aFrame,
 163                                           PRUint8 aWidgetType)=0;
 164
 165   /**
 166     * Should we insert a dropmarker inside of combobox button?
 167    */
 168   virtual PRBool ThemeNeedsComboboxDropmarker()=0;
 169 };
 170
 171 NS_DEFINE_STATIC_IID_ACCESSOR(nsITheme, NS_ITHEME_IID)
 172
 173 // Creator function
 174 extern NS_METHOD NS_NewNativeTheme(nsISupports *aOuter, REFNSIID aIID, void **aResult);
 175
 176 #endif