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