1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 /* service providing platform-specific native rendering for widgets */ 8 9 #ifndef nsITheme_h_ 10 #define nsITheme_h_ 11 12 #include "mozilla/AlreadyAddRefed.h" 13 #include "nsISupports.h" 14 #include "nsID.h" 15 #include "nscore.h" 16 #include "Units.h" 17 18 struct nsRect; 19 class gfxContext; 20 class nsAttrValue; 21 class nsPresContext; 22 class nsDeviceContext; 23 class nsIFrame; 24 class nsAtom; 25 class nsIWidget; 26 27 namespace mozilla { 28 class ComputedStyle; 29 enum class StyleAppearance : uint8_t; 30 enum class StyleScrollbarWidth : uint8_t; 31 namespace layers { 32 class StackingContextHelper; 33 class RenderRootStateManager; 34 } // namespace layers 35 namespace widget { 36 class Theme; 37 } // namespace widget 38 namespace wr { 39 class DisplayListBuilder; 40 class IpcResourceUpdateQueue; 41 } // namespace wr 42 } // namespace mozilla 43 44 // IID for the nsITheme interface 45 // {7329f760-08cb-450f-8225-dae729096dec} 46 #define NS_ITHEME_IID \ 47 { \ 48 0x7329f760, 0x08cb, 0x450f, { \ 49 0x82, 0x25, 0xda, 0xe7, 0x29, 0x09, 0x6d, 0xec \ 50 } \ 51 } 52 53 /** 54 * nsITheme is a service that provides platform-specific native 55 * rendering for widgets. In other words, it provides the necessary 56 * operations to draw a rendering object (an nsIFrame) as a native 57 * widget. 58 * 59 * All the methods on nsITheme take a rendering context or device 60 * context, a frame (the rendering object), and a widget type (one of 61 * the constants in nsThemeConstants.h). 62 */ 63 class nsITheme : public nsISupports { 64 protected: 65 using LayoutDeviceIntMargin = mozilla::LayoutDeviceIntMargin; 66 using LayoutDeviceIntSize = mozilla::LayoutDeviceIntSize; 67 using LayoutDeviceIntCoord = mozilla::LayoutDeviceIntCoord; 68 using StyleAppearance = mozilla::StyleAppearance; 69 using StyleScrollbarWidth = mozilla::StyleScrollbarWidth; 70 using ComputedStyle = mozilla::ComputedStyle; 71 72 public: 73 NS_DECLARE_STATIC_IID_ACCESSOR(NS_ITHEME_IID) 74 75 /** 76 * Draw the actual theme background. 77 * @param aContext the context to draw into 78 * @param aFrame the frame for the widget that we're drawing 79 * @param aWidgetType the -moz-appearance value to draw 80 * @param aRect the rectangle defining the area occupied by the widget 81 * @param aDirtyRect the rectangle that needs to be drawn 82 * @param DrawOverflow whether outlines, shadows and other such overflowing 83 * things should be drawn. Honoring this creates better results for 84 * box-shadow, though it's not a hard requirement. 85 */ 86 enum class DrawOverflow { No, Yes }; 87 NS_IMETHOD DrawWidgetBackground(gfxContext* aContext, nsIFrame* aFrame, 88 StyleAppearance aWidgetType, 89 const nsRect& aRect, const nsRect& aDirtyRect, 90 DrawOverflow = DrawOverflow::Yes) = 0; 91 92 /** 93 * Create WebRender commands for the theme background. 94 * @return true if the theme knows how to create WebRender commands for the 95 * given widget type, false if DrawWidgetBackground need sto be called 96 * instead. 97 */ CreateWebRenderCommandsForWidget(mozilla::wr::DisplayListBuilder & aBuilder,mozilla::wr::IpcResourceUpdateQueue & aResources,const mozilla::layers::StackingContextHelper & aSc,mozilla::layers::RenderRootStateManager * aManager,nsIFrame * aFrame,StyleAppearance aWidgetType,const nsRect & aRect)98 virtual bool CreateWebRenderCommandsForWidget( 99 mozilla::wr::DisplayListBuilder& aBuilder, 100 mozilla::wr::IpcResourceUpdateQueue& aResources, 101 const mozilla::layers::StackingContextHelper& aSc, 102 mozilla::layers::RenderRootStateManager* aManager, nsIFrame* aFrame, 103 StyleAppearance aWidgetType, const nsRect& aRect) { 104 return false; 105 } 106 107 /** 108 * Returns the minimum widths of a scrollbar for a given style, that is, the 109 * minimum width for a vertical scrollbar, and the minimum height of a 110 * horizontal scrollbar. 111 */ 112 enum class Overlay { No, Yes }; 113 struct ScrollbarSizes { 114 LayoutDeviceIntCoord mVertical; 115 LayoutDeviceIntCoord mHorizontal; 116 }; 117 virtual ScrollbarSizes GetScrollbarSizes(nsPresContext*, StyleScrollbarWidth, 118 Overlay) = 0; 119 120 /** 121 * Return the border for the widget, in device pixels. 122 */ 123 [[nodiscard]] virtual LayoutDeviceIntMargin GetWidgetBorder( 124 nsDeviceContext* aContext, nsIFrame* aFrame, 125 StyleAppearance aWidgetType) = 0; 126 127 /** 128 * This method can return false to indicate that the CSS padding 129 * value should be used. Otherwise, it will fill in aResult with the 130 * computed padding, in pixels, and return true. 131 * 132 * XXXldb This ought to be required to return true for non-containers 133 * so that we don't let specified padding that has no effect change 134 * the computed padding and potentially the size. 135 */ 136 virtual bool GetWidgetPadding(nsDeviceContext* aContext, nsIFrame* aFrame, 137 StyleAppearance aWidgetType, 138 LayoutDeviceIntMargin* aResult) = 0; 139 140 /** 141 * On entry, *aResult is positioned at 0,0 and sized to the new size 142 * of aFrame (aFrame->GetSize() may be stale and should not be used). 143 * This method can return false to indicate that no special 144 * overflow area is required by the native widget. Otherwise it will 145 * fill in aResult with the desired overflow area, in appunits, relative 146 * to the frame origin, and return true. 147 * 148 * This overflow area is used to determine what area needs to be 149 * repainted when the widget changes. However, it does not affect the 150 * widget's size or what area is reachable by scrollbars. (In other 151 * words, in layout terms, it affects ink overflow but not 152 * scrollable overflow.) 153 */ GetWidgetOverflow(nsDeviceContext * aContext,nsIFrame * aFrame,StyleAppearance aWidgetType,nsRect * aOverflowRect)154 virtual bool GetWidgetOverflow(nsDeviceContext* aContext, nsIFrame* aFrame, 155 StyleAppearance aWidgetType, 156 /*INOUT*/ nsRect* aOverflowRect) { 157 return false; 158 } 159 160 /** 161 * Get the preferred content-box size of a checkbox / radio button, in app 162 * units. Historically 9px. 163 */ GetCheckboxRadioPrefSize()164 virtual nscoord GetCheckboxRadioPrefSize() { 165 return mozilla::CSSPixel::ToAppUnits(9); 166 } 167 168 /** 169 * Get the minimum border-box size of a widget, in *pixels* (in 170 * |aResult|). If |aIsOverridable| is set to true, this size is a 171 * minimum size; if false, this size is the only valid size for the 172 * widget. 173 */ 174 NS_IMETHOD GetMinimumWidgetSize(nsPresContext* aPresContext, nsIFrame* aFrame, 175 StyleAppearance aWidgetType, 176 mozilla::LayoutDeviceIntSize* aResult, 177 bool* aIsOverridable) = 0; 178 179 enum Transparency { eOpaque = 0, eTransparent, eUnknownTransparency }; 180 181 /** 182 * Returns what we know about the transparency of the widget. 183 */ GetWidgetTransparency(nsIFrame * aFrame,StyleAppearance aWidgetType)184 virtual Transparency GetWidgetTransparency(nsIFrame* aFrame, 185 StyleAppearance aWidgetType) { 186 return eUnknownTransparency; 187 } 188 189 /** 190 * Sets |*aShouldRepaint| to indicate whether an attribute or content state 191 * change should trigger a repaint. Call with null |aAttribute| (and 192 * null |aOldValue|) for content state changes. 193 */ 194 NS_IMETHOD WidgetStateChanged(nsIFrame* aFrame, StyleAppearance aWidgetType, 195 nsAtom* aAttribute, bool* aShouldRepaint, 196 const nsAttrValue* aOldValue) = 0; 197 198 NS_IMETHOD ThemeChanged() = 0; 199 WidgetAppearanceDependsOnWindowFocus(StyleAppearance aWidgetType)200 virtual bool WidgetAppearanceDependsOnWindowFocus( 201 StyleAppearance aWidgetType) { 202 return false; 203 } 204 205 /** 206 * ThemeGeometryType values are used for describing themed nsIFrames in 207 * calls to nsIWidget::UpdateThemeGeometries. We don't simply pass the 208 * -moz-appearance value ("widget type") of the frame because the widget may 209 * want to treat different frames with the same -moz-appearance differently 210 * based on other properties of the frame. So we give the theme a first look 211 * at the frame in nsITheme::ThemeGeometryTypeForWidget and pass the 212 * returned ThemeGeometryType along to the widget. 213 * Each theme backend defines the ThemeGeometryType values it needs in its 214 * own nsITheme subclass. eThemeGeometryTypeUnknown is the only value that's 215 * shared between backends. 216 */ 217 typedef uint8_t ThemeGeometryType; 218 enum { eThemeGeometryTypeUnknown = 0 }; 219 220 /** 221 * Returns the theme geometry type that should be used in the ThemeGeometry 222 * array that's passed to the widget using nsIWidget::UpdateThemeGeometries. 223 * A return value of eThemeGeometryTypeUnknown means that this frame will 224 * not be included in the ThemeGeometry array. 225 */ ThemeGeometryTypeForWidget(nsIFrame * aFrame,StyleAppearance aWidgetType)226 virtual ThemeGeometryType ThemeGeometryTypeForWidget( 227 nsIFrame* aFrame, StyleAppearance aWidgetType) { 228 return eThemeGeometryTypeUnknown; 229 } 230 231 /** 232 * Can the nsITheme implementation handle this widget? 233 */ 234 virtual bool ThemeSupportsWidget(nsPresContext* aPresContext, 235 nsIFrame* aFrame, 236 StyleAppearance aWidgetType) = 0; 237 238 virtual bool WidgetIsContainer(StyleAppearance aWidgetType) = 0; 239 240 /** 241 * Does the nsITheme implementation draw its own focus ring for this widget? 242 */ 243 virtual bool ThemeDrawsFocusForWidget(nsIFrame*, StyleAppearance) = 0; 244 245 /** 246 * Whether we want an inner focus ring for buttons and such. 247 * 248 * Usually, we don't want it if we have our own focus indicators, but windows 249 * is special, because it wants it even though focus also alters the border 250 * color and such. 251 */ ThemeWantsButtonInnerFocusRing(nsIFrame * aFrame,StyleAppearance aAppearance)252 virtual bool ThemeWantsButtonInnerFocusRing(nsIFrame* aFrame, 253 StyleAppearance aAppearance) { 254 return !ThemeDrawsFocusForWidget(aFrame, aAppearance); 255 } 256 257 /** 258 * Should we insert a dropmarker inside of combobox button? 259 */ 260 virtual bool ThemeNeedsComboboxDropmarker() = 0; 261 262 virtual bool ThemeSupportsScrollbarButtons() = 0; 263 }; 264 265 NS_DEFINE_STATIC_IID_ACCESSOR(nsITheme, NS_ITHEME_IID) 266 267 // Singleton accessor functions, these should never return null. 268 // 269 // Do not use directly, use nsPresContext::Theme instead. 270 extern already_AddRefed<nsITheme> do_GetNativeThemeDoNotUseDirectly(); 271 extern already_AddRefed<nsITheme> do_GetBasicNativeThemeDoNotUseDirectly(); 272 extern already_AddRefed<nsITheme> do_GetRDMThemeDoNotUseDirectly(); 273 274 // Native theme creation function, these should never return null. 275 extern already_AddRefed<mozilla::widget::Theme> 276 do_CreateNativeThemeDoNotUseDirectly(); 277 278 #endif 279