docs/latex/wx/renderer.tex

   1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2 %% Name:        renderer.tex
   3 %% Purpose:     wxRenderer and wxRendererNative documentation
   4 %% Author:      Vadim Zeitlin
   5 %% Modified by:
   6 %% Created:     06.08.03
   7 %% RCS-ID:      $Id$
   8 %% Copyright:   (c) 2003 Vadim Zeitlin <vadim@wxwindows.org>
   9 %% License:     wxWindows license
  10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  11
  12 \section{\class{wxRendererNative}}\label{wxrenderernative}
  13
  14 First, a brief introduction to wxRenderer and why it is needed.
  15
  16 Usually wxWidgets uses the underlying low level GUI system to draw all the
  17 controls - this is what we mean when we say that it is a ``native'' framework.
  18 However not all controls exist under all (or even any) platforms and in this
  19 case wxWidgets provides a default, generic, implementation of them written in
  20 wxWidgets itself.
  21
  22 These controls don't have the native appearance if only the standard
  23 line drawing and other graphics primitives are used, because the native
  24 appearance is different under different platforms while the lines are always
  25 drawn in the same way.
  26
  27 This is why we have renderers: wxRenderer is a class which virtualizes the
  28 drawing, i.e. it abstracts the drawing operations and allows you to draw say, a
  29 button, without caring about exactly how this is done. Of course, as we
  30 can draw the button differently in different renderers, this also allows us to
  31 emulate the native look and feel.
  32
  33 So the renderers work by exposing a large set of high-level drawing functions
  34 which are used by the generic controls. There is always a default global
  35 renderer but it may be changed or extended by the user, see
  36 \helpref{Render sample}{samplerender}.
  37
  38 All drawing functions take some standard parameters:
  39 \begin{itemize}
  40 \item \arg{win} is the window being drawn. It is normally not used and when
  41 it is it should only be used as a generic \helpref{wxWindow}{wxwindow}
  42 (in order to get its low level handle, for example), but you should
  43 \emph{not} assume that it is of some given type as the same renderer
  44 function may be reused for drawing different kinds of control.
  45 \item \arg{dc} is the \helpref{wxDC}{wxdc} to draw on. Only this device
  46 context should be used for drawing. It is not necessary to restore
  47 pens and brushes for it on function exit but, on the other hand, you
  48 shouldn't assume that it is in any specific state on function entry:
  49 the rendering functions should always prepare it.
  50 \item \arg{rect} the bounding rectangle for the element to be drawn.
  51 \item \arg{flags} the optional flags (none by default) which can be a
  52 combination of the \texttt{wxCONTROL\_XXX} constants below.
  53 \end{itemize}
  54
  55 Note that each drawing function restores the \helpref{wxDC}{wxdc} attributes if
  56 it changes them, so it is safe to assume that the same pen, brush and colours
  57 that were active before the call to this function are still in effect after it.
  58
  59
  60 \wxheading{Constants}
  61
  62 The following rendering flags are defined:
  63
  64 \begin{verbatim}
  65 enum
  66 {
  67     wxCONTROL_DISABLED   = 0x00000001,  // control is disabled
  68     wxCONTROL_FOCUSED    = 0x00000002,  // currently has keyboard focus
  69     wxCONTROL_PRESSED    = 0x00000004,  // (button) is pressed
  70     wxCONTROL_ISDEFAULT  = 0x00000008,  // only applies to the buttons
  71     wxCONTROL_ISSUBMENU  = wxCONTROL_ISDEFAULT, // only for menu items
  72     wxCONTROL_EXPANDED   = wxCONTROL_ISDEFAULT, // only for the tree items
  73     wxCONTROL_CURRENT    = 0x00000010,  // mouse is currently over the control
  74     wxCONTROL_SELECTED   = 0x00000020,  // selected item in e.g. listbox
  75     wxCONTROL_CHECKED    = 0x00000040,  // (check/radio button) is checked
  76     wxCONTROL_CHECKABLE  = 0x00000080,  // (menu) item can be checked
  77     wxCONTROL_UNDETERMINED = wxCONTROL_CHECKABLE  // (check) undetermined state
  78     wxCONTROL_UPICON     = 0x00000100,  // header button has an up arrow icon
  79     wxCONTROL_DOWNICON   = 0x00000200,  // header button has a down arrow icon
  80
  81 };
  82 \end{verbatim}
  83
  84 \wxheading{Derived from}
  85
  86 No base class
  87
  88 \wxheading{Include files}
  89
  90 <wx/renderer.h>
  91
  92
  93 \latexignore{\rtfignore{\wxheading{Members}}}
  94
  95
  96 \membersection{wxRendererNative::\destruct{wxRendererNative}}\label{wxrenderernativedtor}
  97
  98 \func{}{\destruct{wxRendererNative}}{\void}
  99
 100 Virtual destructor as for any base class.
 101
 102
 103 \membersection{wxRendererNative::DrawCheckBox}\label{wxrenderernativedrawcheckbox}
 104
 105 \func{void}{DrawCheckBox}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 106
 107 Draw a check box (used by wxDataViewCtrl).
 108
 109 \arg{flags} may have the \texttt{wxCONTROL\_CHECKED}, \texttt{wxCONTROL\_CURRENT} or
 110 \texttt{wxCONTROL\_UNDETERMINED} bit set.
 111
 112
 113 \membersection{wxRendererNative::DrawComboBoxDropButton}\label{wxrenderernativedrawcomboboxdropbutton}
 114
 115 \func{void}{DrawComboBoxDropButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 116
 117 Draw a button like the one used by \helpref{wxComboBox}{wxcombobox} to show a
 118 drop down window. The usual appearance is a downwards pointing arrow.
 119
 120 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 121
 122
 123 \membersection{wxRendererNative::DrawDropArrow}\label{wxrenderernativedrawdroparrow}
 124
 125 \func{void}{DrawDropArrow}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 126
 127 Draw a drop down arrow that is suitable for use outside a combo box. Arrow will have
 128 transparent background.
 129
 130 \arg{rect} is not entirely filled by the arrow. Instead, you should use bounding
 131 rectangle of a drop down button which arrow matches the size you need.
 132 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 133
 134
 135 \membersection{wxRendererNative::DrawHeaderButton}\label{wxrenderernativedrawheaderbutton}
 136
 137 \func{void}{DrawHeaderButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}, \param{wxHeaderButtonParams* }{params = NULL}}
 138
 139 Draw the header control button (used by \helpref{wxListCtrl}{wxlistctrl}).
 140
 141
 142 \membersection{wxRendererNative::DrawPushButton}\label{wxrenderernativedrawpushbutton}
 143
 144 \func{void}{DrawPushButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 145
 146 Draw a blank push button that looks very similar to \helpref{wxButton}{wxbutton}.
 147
 148 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED}, \texttt{wxCONTROL\_CURRENT} or
 149 \texttt{wxCONTROL\_ISDEFAULT} bit set.
 150
 151
 152 \membersection{wxRendererNative::DrawSplitterBorder}\label{wxrenderernativedrawsplitterborder}
 153
 154 \func{void}{DrawSplitterBorder}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 155
 156 Draw the border for sash window: this border must be such that the sash
 157 drawn by \helpref{DrawSash}{wxrenderernativedrawsplittersash} blends into it
 158 well.
 159
 160
 161 \membersection{wxRendererNative::DrawSplitterSash}\label{wxrenderernativedrawsplittersash}
 162
 163 \func{void}{DrawSplitterSash}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxSize\& }{size}, \param{wxCoord }{position}, \param{wxOrientation }{orient}, \param{int }{flags = 0}}
 164
 165 Draw a sash. The \arg{orient} parameter defines whether the sash should be
 166 vertical or horizontal and how the \arg{position} should be interpreted.
 167
 168
 169 \membersection{wxRendererNative::DrawTreeItemButton}\label{wxrenderernativedrawtreeitembutton}
 170
 171 \func{void}{DrawTreeItemButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 172
 173 Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 174 button the \arg{flags} parameter must contain {\tt wxCONTROL\_EXPANDED} bit.
 175
 176
 177 \membersection{wxRendererNative::Get}\label{wxrenderernativeget}
 178
 179 \func{wxRendererNative\&}{Get}{\void}
 180
 181 Return the currently used renderer.
 182
 183
 184 \membersection{wxRendererNative::GetDefault}\label{wxrenderernativegetdefault}
 185
 186 \func{wxRendererNative\&}{GetDefault}{\void}
 187
 188 Return the default (native) implementation for this platform -- this is also
 189 the one used by default but this may be changed by calling
 190 \helpref{Set}{wxrenderernativeset} in which case the return value of this
 191 method may be different from the return value of \helpref{Get}{wxrenderernativeget}.
 192
 193
 194 \membersection{wxRendererNative::GetGeneric}\label{wxrenderernativegetgeneric}
 195
 196 \func{wxRendererNative\&}{GetGeneric}{\void}
 197
 198 Return the generic implementation of the renderer. Under some platforms, this
 199 is the default renderer implementation, others have platform-specific default
 200 renderer which can be retrieved by calling \helpref{GetDefault}{wxrenderernativegetdefault}.
 201
 202
 203 \membersection{wxRendererNative::GetHeaderButtonHeight}\label{wxrenderernativegetheaderbuttonheight}
 204
 205 \func{int}{GetHeaderButtonHeight}{\param{const wxWindow* }{win}}
 206
 207 Returns the height of a header button, either a fixed platform height if available, or a
 208 generic height based on the window's font.
 209
 210
 211 \membersection{wxRendererNative::GetSplitterParams}\label{wxrenderernativegetsplitterparams}
 212
 213 \func{wxSplitterRenderParams}{GetSplitterParams}{\param{const wxWindow* }{win}}
 214
 215 Get the splitter parameters, see
 216 \helpref{wxSplitterRenderParams}{wxsplitterrenderparams}.
 217
 218
 219 \membersection{wxRendererNative::GetVersion}\label{wxrenderernativegetversion}
 220
 221 \constfunc{wxRendererVersion}{GetVersion}{\void}
 222
 223 This function is used for version checking: \helpref{Load}{wxrenderernativeload}
 224 refuses to load any shared libraries implementing an older or incompatible
 225 version.
 226
 227 The implementation of this method is always the same in all renderers (simply
 228 construct \helpref{wxRendererVersion}{wxrendererversion} using the
 229 {\tt wxRendererVersion::Current\_XXX} values), but it has to be in the derived,
 230 not base, class, to detect mismatches between the renderers versions and so you
 231 have to implement it anew in all renderers.
 232
 233
 234 \membersection{wxRendererNative::Load}\label{wxrenderernativeload}
 235
 236 \func{wxRendererNative*}{Load}{\param{const wxString\& }{name}}
 237
 238 Load the renderer from the specified DLL, the returned pointer must be
 239 deleted by caller if not {\tt NULL} when it is not used any more.
 240
 241 The \arg{name} should be just the base name of the renderer and not the full
 242 name of the DLL file which is constructed differently (using
 243 \helpref{wxDynamicLibrary::CanonicalizePluginName}{wxdynamiclibrarycanonicalizepluginname})
 244 on different systems.
 245
 246
 247 \membersection{wxRendererNative::Set}\label{wxrenderernativeset}
 248
 249 \func{wxRendererNative*}{Set}{\param{wxRendererNative* }{renderer}}
 250
 251 Set the renderer to use, passing {\tt NULL} reverts to using the default
 252 renderer (the global renderer must always exist).
 253
 254 Return the previous renderer used with Set() or {\tt NULL} if none.