interface/renderer.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        renderer.h
   3 // Purpose:     documentation for wxSplitterRenderParams class
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxSplitterRenderParams
  11     @wxheader{renderer.h}
  12
  13     This is just a simple @c struct used as a return value of
  14     wxRendererNative::GetSplitterParams.
  15
  16     It doesn't have any methods and all of its fields are constant and so can be
  17     only examined but not modified.
  18
  19     @library{wxbase}
  20     @category{FIXME}
  21 */
  22 class wxSplitterRenderParams
  23 {
  24 public:
  25     /**
  26         const wxCoord border
  27
  28         The width of the border drawn by the splitter inside it, may be 0.
  29     */
  30
  31
  32     /**
  33         const bool isHotSensitive
  34
  35         @true if the sash changes appearance when the mouse passes over it, @false
  36         otherwise.
  37     */
  38
  39
  40     /**
  41         const wxCoord widthSash
  42
  43         The width of the splitter sash.
  44     */
  45 };
  46
  47
  48 /**
  49     @class wxDelegateRendererNative
  50     @wxheader{renderer.h}
  51
  52     wxDelegateRendererNative allows reuse of renderers code by forwarding all the
  53     wxRendererNative methods to the given object and
  54     thus allowing you to only modify some of its methods -- without having to
  55     reimplement all of them.
  56
  57     Note that the "normal'', inheritance-based approach, doesn't work with the
  58     renderers as it is impossible to derive from a class unknown at compile-time
  59     and the renderer is only chosen at run-time. So suppose that you want to only
  60     add something to the drawing of the tree control buttons but leave all the
  61     other methods unchanged -- the only way to do it, considering that the renderer
  62     class which you want to customize might not even be written yet when you write
  63     your code (it could be written later and loaded from a DLL during run-time), is
  64     by using this class.
  65
  66     Except for the constructor, it has exactly the same methods as
  67     wxRendererNative and their implementation is
  68     trivial: they are simply forwarded to the real renderer. Note that the "real''
  69     renderer may, in turn, be a wxDelegateRendererNative as well and that there may
  70     be arbitrarily many levels like this -- but at the end of the chain there must
  71     be a real renderer which does the drawing.
  72
  73     @library{wxcore}
  74     @category{FIXME}
  75 */
  76 class wxDelegateRendererNative : public wxRendererNative
  77 {
  78 public:
  79     //@{
  80     /**
  81         The default constructor does the same thing as the other one except that it
  82         uses the @ref wxRendererNative::getgeneric "generic renderer" instead of the
  83         user-specified @e rendererNative.
  84
  85         In any case, this sets up the delegate renderer object to follow all calls to
  86         the specified real renderer.
  87
  88         Note that this object does not take ownership of (i.e. won't delete)
  89         @e rendererNative.
  90     */
  91     wxDelegateRendererNative();
  92     wxDelegateRendererNative(wxRendererNative& rendererNative);
  93     //@}
  94
  95     /**
  96         This class also provides all the virtual methods of
  97         wxRendererNative, please refer to that class
  98         documentation for the details.
  99     */
 100     DrawXXX(...);
 101 };
 102
 103
 104 /**
 105     @class wxRendererNative
 106     @wxheader{renderer.h}
 107
 108     First, a brief introduction to wxRenderer and why it is needed.
 109
 110     Usually wxWidgets uses the underlying low level GUI system to draw all the
 111     controls - this is what we mean when we say that it is a "native'' framework.
 112     However not all controls exist under all (or even any) platforms and in this
 113     case wxWidgets provides a default, generic, implementation of them written in
 114     wxWidgets itself.
 115
 116     These controls don't have the native appearance if only the standard
 117     line drawing and other graphics primitives are used, because the native
 118     appearance is different under different platforms while the lines are always
 119     drawn in the same way.
 120
 121     This is why we have renderers: wxRenderer is a class which virtualizes the
 122     drawing, i.e. it abstracts the drawing operations and allows you to draw say, a
 123     button, without caring about exactly how this is done. Of course, as we
 124     can draw the button differently in different renderers, this also allows us to
 125     emulate the native look and feel.
 126
 127     So the renderers work by exposing a large set of high-level drawing functions
 128     which are used by the generic controls. There is always a default global
 129     renderer but it may be changed or extended by the user, see
 130     @ref overview_samplerender "Render sample".
 131
 132     All drawing functions take some standard parameters:
 133
 134      @e win is the window being drawn. It is normally not used and when
 135     it is it should only be used as a generic wxWindow
 136     (in order to get its low level handle, for example), but you should
 137     not assume that it is of some given type as the same renderer
 138     function may be reused for drawing different kinds of control.
 139      @e dc is the wxDC to draw on. Only this device
 140     context should be used for drawing. It is not necessary to restore
 141     pens and brushes for it on function exit but, on the other hand, you
 142     shouldn't assume that it is in any specific state on function entry:
 143     the rendering functions should always prepare it.
 144      @e rect the bounding rectangle for the element to be drawn.
 145      @e flags the optional flags (none by default) which can be a
 146     combination of the @c wxCONTROL_XXX constants below.
 147
 148     Note that each drawing function restores the wxDC attributes if
 149     it changes them, so it is safe to assume that the same pen, brush and colours
 150     that were active before the call to this function are still in effect after it.
 151
 152     @library{wxcore}
 153     @category{gdi}
 154 */
 155 class wxRendererNative
 156 {
 157 public:
 158     /**
 159         Virtual destructor as for any base class.
 160     */
 161     ~wxRendererNative();
 162
 163     /**
 164         Draw a check box (used by wxDataViewCtrl).
 165
 166         @e flags may have the @c wxCONTROL_CHECKED, @c wxCONTROL_CURRENT or
 167         @c wxCONTROL_UNDETERMINED bit set.
 168     */
 169     void DrawCheckBox(wxWindow * win, wxDC& dc, const wxRect& rect,
 170                       int flags);
 171
 172     /**
 173         Draw a button like the one used by wxComboBox to show a
 174         drop down window. The usual appearance is a downwards pointing arrow.
 175
 176         @e flags may have the @c wxCONTROL_PRESSED or @c wxCONTROL_CURRENT bit set.
 177     */
 178     void DrawComboBoxDropButton(wxWindow * win, wxDC& dc,
 179                                 const wxRect& rect,
 180                                 int flags);
 181
 182     /**
 183         Draw a drop down arrow that is suitable for use outside a combo box. Arrow will
 184         have
 185         transparent background.
 186
 187         @e rect is not entirely filled by the arrow. Instead, you should use bounding
 188         rectangle of a drop down button which arrow matches the size you need.
 189         @e flags may have the @c wxCONTROL_PRESSED or @c wxCONTROL_CURRENT bit set.
 190     */
 191     void DrawDropArrow(wxWindow * win, wxDC& dc, const wxRect& rect,
 192                        int flags);
 193
 194     /**
 195         Draw a focus rectangle using the specified rectangle.
 196         wxListCtrl. The only supported flags is
 197         @c wxCONTROL_SELECTED for items which are selected.
 198     */
 199     void DrawFocusRect(wxWindow* win, wxDC& dc, const wxRect& rect,
 200                        int flags = 0);
 201
 202     /**
 203         Draw the header control button (used, for example, by
 204         wxListCtrl).  Depending on platforms the
 205         @e flags parameter may support the @c wxCONTROL_SELECTED
 206         @c wxCONTROL_DISABLED and @c wxCONTROL_CURRENT bits.
 207         The @e sortArrow parameter can be one of
 208         @c wxHDR_SORT_ICON_NONE, @c wxHDR_SORT_ICON_UP, or
 209         @c wxHDR_SORT_ICON_DOWN.  Additional values controlling the
 210         drawing of a text or bitmap label can be passed in @e params.  The
 211         value returned is the optimal width to contain the the unabreviated
 212         label text or bitmap, the sort arrow if present, and internal margins.
 213     */
 214     int DrawHeaderButton(wxWindow* win, wxDC& dc, const wxRect& rect,
 215                          int flags = 0,
 216                          wxHeaderSortIconType sortArrow = wxHDR_SORT_ICON_NONE,
 217                          wxHeaderButtonParams* params = @NULL);
 218
 219     /**
 220         Draw a selection rectangle underneath the text as used e.g. in a
 221         wxListCtrl. The supported @e flags are
 222         @c wxCONTROL_SELECTED for items which are selected (e.g. often a blue
 223         rectangle) and @c wxCONTROL_CURRENT for the item that has the focus
 224         (often a dotted line around the item's text). @c wxCONTROL_FOCUSED may
 225         be used to indicate if the control has the focus (othewise the the selection
 226         rectangle is e.g. often grey and not blue). This may be ignored by the renderer
 227         or deduced by the code directly from the @e win.
 228     */
 229     void DrawItemSelectionRect(wxWindow* win, wxDC& dc,
 230                                const wxRect& rect,
 231                                int flags = 0);
 232
 233     /**
 234         Draw a blank push button that looks very similar to wxButton.
 235
 236         @e flags may have the @c wxCONTROL_PRESSED, @c wxCONTROL_CURRENT or
 237         @c wxCONTROL_ISDEFAULT bit set.
 238     */
 239     void DrawPushButton(wxWindow * win, wxDC& dc, const wxRect& rect,
 240                         int flags);
 241
 242     /**
 243         Draw the border for sash window: this border must be such that the sash
 244         drawn by @ref drawsplittersash() DrawSash blends into it
 245         well.
 246     */
 247     void DrawSplitterBorder(wxWindow* win, wxDC& dc,
 248                             const wxRect& rect,
 249                             int flags = 0);
 250
 251     /**
 252         Draw a sash. The @e orient parameter defines whether the sash should be
 253         vertical or horizontal and how the @e position should be interpreted.
 254     */
 255     void DrawSplitterSash(wxWindow* win, wxDC& dc,
 256                           const wxSize& size,
 257                           wxCoord position,
 258                           wxOrientation orient,
 259                           int flags = 0);
 260
 261     /**
 262         Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 263         button the @e flags parameter must contain @c wxCONTROL_EXPANDED bit.
 264     */
 265     void DrawTreeItemButton(wxWindow* win, wxDC& dc,
 266                             const wxRect& rect,
 267                             int flags = 0);
 268
 269     /**
 270         Return the currently used renderer.
 271     */
 272 #define wxRendererNative Get()     /* implementation is private */
 273
 274     /**
 275         Return the default (native) implementation for this platform -- this is also
 276         the one used by default but this may be changed by calling
 277         Set() in which case the return value of this
 278         method may be different from the return value of Get().
 279     */
 280     wxRendererNative GetDefault();
 281
 282     /**
 283         Return the generic implementation of the renderer. Under some platforms, this
 284         is the default renderer implementation, others have platform-specific default
 285         renderer which can be retrieved by calling GetDefault().
 286     */
 287     wxRendererNative GetGeneric();
 288
 289     /**
 290         Returns the height of a header button, either a fixed platform height if
 291         available, or a
 292         generic height based on the window's font.
 293     */
 294     int GetHeaderButtonHeight(const wxWindow* win);
 295
 296     /**
 297         Get the splitter parameters, see
 298         wxSplitterRenderParams.
 299     */
 300     wxSplitterRenderParams GetSplitterParams(const wxWindow* win);
 301
 302     /**
 303         This function is used for version checking: Load()
 304         refuses to load any shared libraries implementing an older or incompatible
 305         version.
 306
 307         The implementation of this method is always the same in all renderers (simply
 308         construct wxRendererVersion using the
 309         @c wxRendererVersion::Current_XXX values), but it has to be in the derived,
 310         not base, class, to detect mismatches between the renderers versions and so you
 311         have to implement it anew in all renderers.
 312     */
 313     wxRendererVersion GetVersion();
 314
 315     /**
 316         Load the renderer from the specified DLL, the returned pointer must be
 317         deleted by caller if not @NULL when it is not used any more.
 318
 319         The @e name should be just the base name of the renderer and not the full
 320         name of the DLL file which is constructed differently (using
 321         wxDynamicLibrary::CanonicalizePluginName)
 322         on different systems.
 323     */
 324     wxRendererNative* Load(const wxString& name);
 325
 326     /**
 327         Set the renderer to use, passing @NULL reverts to using the default
 328         renderer (the global renderer must always exist).
 329
 330         Return the previous renderer used with Set() or @NULL if none.
 331     */
 332 #define wxRendererNative* Set(wxRendererNative* renderer)     /* implementation is private */
 333 };
 334
 335
 336 /**
 337     @class wxRendererVersion
 338     @wxheader{renderer.h}
 339
 340     This simple struct represents the wxRendererNative
 341     interface version and is only used as the return value of
 342     wxRendererNative::GetVersion.
 343
 344     The version has two components: the version itself and the age. If the main
 345     program and the renderer have different versions they are never compatible with
 346     each other because the version is only changed when an existing virtual
 347     function is modified or removed. The age, on the other hand, is incremented
 348     each time a new virtual method is added and so, at least for the compilers
 349     using a common C++ object model, the calling program is compatible with any
 350     renderer which has the age greater or equal to its age. This verification is
 351     done by IsCompatible method.
 352
 353     @library{wxbase}
 354     @category{FIXME}
 355 */
 356 class wxRendererVersion
 357 {
 358 public:
 359     /**
 360         Checks if the main program is compatible with the renderer having the version
 361         @e ver, returns @true if it is and @false otherwise.
 362
 363         This method is used by
 364         wxRendererNative::Load to determine whether a
 365         renderer can be used.
 366     */
 367     static bool IsCompatible(const wxRendererVersion& ver);
 368
 369     /**
 370         const int age
 371
 372         The age component.
 373     */
 374
 375
 376     /**
 377         const int version
 378
 379         The version component.
 380     */
 381 };