interface/renderer.h

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