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:     wxWidgets 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 \wxheading{Constants}
  56
  57 The following rendering flags are defined:
  58
  59 \begin{verbatim}
  60 enum
  61 {
  62     wxCONTROL_DISABLED   = 0x00000001,  // control is disabled
  63     wxCONTROL_FOCUSED    = 0x00000002,  // currently has keyboard focus
  64     wxCONTROL_PRESSED    = 0x00000004,  // (button) is pressed
  65     wxCONTROL_ISDEFAULT  = 0x00000008,  // only applies to the buttons
  66     wxCONTROL_ISSUBMENU  = wxCONTROL_ISDEFAULT, // only for menu items
  67     wxCONTROL_EXPANDED   = wxCONTROL_ISDEFAULT, // only for the tree items
  68     wxCONTROL_CURRENT    = 0x00000010,  // mouse is currently over the control
  69     wxCONTROL_SELECTED   = 0x00000020,  // selected item in e.g. listbox
  70     wxCONTROL_CHECKED    = 0x00000040,  // (check/radio button) is checked
  71     wxCONTROL_CHECKABLE  = 0x00000080   // (menu) item can be checked
  72 };
  73 \end{verbatim}
  74
  75 \wxheading{Derived from}
  76
  77 No base class
  78
  79 \wxheading{Include files}
  80
  81 <wx/renderer.h>
  82
  83
  84 \latexignore{\rtfignore{\wxheading{Members}}}
  85
  86
  87 \membersection{wxRendererNative::\destruct{wxRendererNative}}\label{wxrenderernativedtor}
  88
  89 \func{}{\destruct{wxRendererNative}}{\void}
  90
  91 Virtual destructor as for any base class.
  92
  93
  94 \membersection{wxRendererGeneric::DrawComboBoxDropButton}
  95
  96 \func{void}{DrawComboBoxDropButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
  97
  98 Draw a button like the one used by \helpref{wxComboBox}{wxcombobox} to show a
  99 drop down window. The usual appearance is a downwards pointing arrow.
 100
 101 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} bit set.
 102
 103
 104 \membersection{wxRendererNative::DrawHeaderButton}\label{wxrenderernativedrawheaderbutton}
 105
 106 \func{void}{DrawHeaderButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 107
 108 Draw the header control button (used by \helpref{wxListCtrl}{wxlistctrl}).
 109
 110
 111 \membersection{wxRendererNative::DrawSplitterBorder}\label{wxrenderernativedrawsplitterborder}
 112
 113 \func{void}{DrawSplitterBorder}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 114
 115 Draw the border for sash window: this border must be such that the sash
 116 drawn by \helpref{DrawSash}{wxrenderernativedrawsplittersash} blends into it
 117 well.
 118
 119
 120 \membersection{wxRendererNative::DrawSplitterSash}\label{wxrenderernativedrawsplittersash}
 121
 122 \func{void}{DrawSplitterSash}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxSize\& }{size}, \param{wxCoord }{position}, \param{wxOrientation }{orient}, \param{int }{flags = 0}}
 123
 124 Draw a sash. The \arg{orient} parameter defines whether the sash should be
 125 vertical or horizontal and how should the \arg{position} be interpreted.
 126
 127
 128 \membersection{wxRendererNative::DrawTreeItemButton}\label{wxrenderernativedrawtreeitembutton}
 129
 130 \func{void}{DrawTreeItemButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 131
 132 Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 133 button the \arg{flags} parameter must contain {\tt wxCONTROL\_EXPANDED} bit.
 134
 135
 136 \membersection{wxRendererNative::Get}\label{wxrenderernativeget}
 137
 138 \func{wxRendererNative\&}{Get}{\void}
 139
 140 Return the currently used renderer.
 141
 142
 143 \membersection{wxRendererNative::GetDefault}\label{wxrenderernativegetdefault}
 144
 145 \func{wxRendererNative\&}{GetDefault}{\void}
 146
 147 Return the default (native) implementation for this platform -- this is also
 148 the one used by default but this may be changed by calling
 149 \helpref{Set}{wxrenderernativeset} in which case the return value of this
 150 method may be different from the return value of \helpref{Get}{wxrenderernativeget}.
 151
 152
 153 \membersection{wxRendererNative::GetGeneric}\label{wxrenderernativegetgeneric}
 154
 155 \func{wxRendererNative\&}{GetGeneric}{\void}
 156
 157 Return the generic implementation of the renderer. Under some platforms, this
 158 is the default renderer implementation, others have platform-specific default
 159 renderer which can be retrieved by calling \helpref{GetDefault}{wxrenderernativegetdefault}.
 160
 161
 162 \membersection{wxRendererNative::GetSplitterParams}\label{wxrenderernativegetsplitterparams}
 163
 164 \func{wxSplitterRenderParams}{GetSplitterParams}{\param{const wxWindow* }{win}}
 165
 166 Get the splitter parameters, see
 167 \helpref{wxSplitterRenderParams}{wxsplitterrenderparams}.
 168
 169
 170 \membersection{wxRendererNative::GetVersion}\label{wxrenderernativegetversion}
 171
 172 \constfunc{wxRendererVersion}{GetVersion}{\void}
 173
 174 This function is used for version checking: \helpref{Load}{wxrenderernativeload}
 175 refuses to load any shared libraries implementing an older or incompatible
 176 version.
 177
 178 The implementation of this method is always the same in all renderers (simply
 179 construct \helpref{wxRendererVersion}{wxrendererversion} using the
 180 {\tt wxRendererVersion::Current\_XXX} values), but it has to be in the derived,
 181 not base, class, to detect mismatches between the renderers versions and so you
 182 have to implement it anew in all renderers.
 183
 184
 185 \membersection{wxRendererNative::Load}\label{wxrenderernativeload}
 186
 187 \func{wxRendererNative*}{Load}{\param{const wxString\& }{name}}
 188
 189 Load the renderer from the specified DLL, the returned pointer must be
 190 deleted by caller if not {\tt NULL} when it is not used any more.
 191
 192 The \arg{name} should be just the base name of the renderer and not the full
 193 name of the DLL file which is constructed differently (using
 194 \helpref{wxDynamicLibrary::CanonicalizePluginName}{wxdynamiclibrarycanonicalizepluginname})
 195 on different systems.
 196
 197
 198 \membersection{wxRendererNative::Set}\label{wxrenderernativeset}
 199
 200 \func{wxRendererNative*}{Set}{\param{wxRendererNative* }{renderer}}
 201
 202 Set the renderer to use, passing {\tt NULL} reverts to using the default
 203 renderer (the global renderer must always exist).
 204
 205 Return the previous renderer used with Set() or {\tt NULL} if none.
 206