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 \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{wxRendererNative::DrawComboBoxDropButton}\label{wxrenderernativedrawcomboboxdropbutton}
  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} or \texttt{wxCONTROL\_CURRENT} bit set.
 102
 103
 104 \membersection{wxRendererNative::DrawDropArrow}\label{wxrenderernativedrawdroparrow}
 105
 106 \func{void}{DrawDropArrow}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 107
 108 Draw a drop down arrow that is suitable for use outside a combo box. Arrow will have
 109 transparent background.
 110
 111 \arg{rect} is not entirely filled by the arrow. Instead, you should use bounding
 112 rectangle of a drop down button which arrow matches the size you need.
 113 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 114
 115
 116 \membersection{wxRendererNative::DrawHeaderButton}\label{wxrenderernativedrawheaderbutton}
 117
 118 \func{void}{DrawHeaderButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 119
 120 Draw the header control button (used by \helpref{wxListCtrl}{wxlistctrl}).
 121
 122
 123 \membersection{wxRendererNative::DrawSplitterBorder}\label{wxrenderernativedrawsplitterborder}
 124
 125 \func{void}{DrawSplitterBorder}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 126
 127 Draw the border for sash window: this border must be such that the sash
 128 drawn by \helpref{DrawSash}{wxrenderernativedrawsplittersash} blends into it
 129 well.
 130
 131
 132 \membersection{wxRendererNative::DrawSplitterSash}\label{wxrenderernativedrawsplittersash}
 133
 134 \func{void}{DrawSplitterSash}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxSize\& }{size}, \param{wxCoord }{position}, \param{wxOrientation }{orient}, \param{int }{flags = 0}}
 135
 136 Draw a sash. The \arg{orient} parameter defines whether the sash should be
 137 vertical or horizontal and how the \arg{position} should be interpreted.
 138
 139
 140 \membersection{wxRendererNative::DrawTreeItemButton}\label{wxrenderernativedrawtreeitembutton}
 141
 142 \func{void}{DrawTreeItemButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 143
 144 Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 145 button the \arg{flags} parameter must contain {\tt wxCONTROL\_EXPANDED} bit.
 146
 147
 148 \membersection{wxRendererNative::Get}\label{wxrenderernativeget}
 149
 150 \func{wxRendererNative\&}{Get}{\void}
 151
 152 Return the currently used renderer.
 153
 154
 155 \membersection{wxRendererNative::GetDefault}\label{wxrenderernativegetdefault}
 156
 157 \func{wxRendererNative\&}{GetDefault}{\void}
 158
 159 Return the default (native) implementation for this platform -- this is also
 160 the one used by default but this may be changed by calling
 161 \helpref{Set}{wxrenderernativeset} in which case the return value of this
 162 method may be different from the return value of \helpref{Get}{wxrenderernativeget}.
 163
 164
 165 \membersection{wxRendererNative::GetGeneric}\label{wxrenderernativegetgeneric}
 166
 167 \func{wxRendererNative\&}{GetGeneric}{\void}
 168
 169 Return the generic implementation of the renderer. Under some platforms, this
 170 is the default renderer implementation, others have platform-specific default
 171 renderer which can be retrieved by calling \helpref{GetDefault}{wxrenderernativegetdefault}.
 172
 173
 174 \membersection{wxRendererNative::GetSplitterParams}\label{wxrenderernativegetsplitterparams}
 175
 176 \func{wxSplitterRenderParams}{GetSplitterParams}{\param{const wxWindow* }{win}}
 177
 178 Get the splitter parameters, see
 179 \helpref{wxSplitterRenderParams}{wxsplitterrenderparams}.
 180
 181
 182 \membersection{wxRendererNative::GetVersion}\label{wxrenderernativegetversion}
 183
 184 \constfunc{wxRendererVersion}{GetVersion}{\void}
 185
 186 This function is used for version checking: \helpref{Load}{wxrenderernativeload}
 187 refuses to load any shared libraries implementing an older or incompatible
 188 version.
 189
 190 The implementation of this method is always the same in all renderers (simply
 191 construct \helpref{wxRendererVersion}{wxrendererversion} using the
 192 {\tt wxRendererVersion::Current\_XXX} values), but it has to be in the derived,
 193 not base, class, to detect mismatches between the renderers versions and so you
 194 have to implement it anew in all renderers.
 195
 196
 197 \membersection{wxRendererNative::Load}\label{wxrenderernativeload}
 198
 199 \func{wxRendererNative*}{Load}{\param{const wxString\& }{name}}
 200
 201 Load the renderer from the specified DLL, the returned pointer must be
 202 deleted by caller if not {\tt NULL} when it is not used any more.
 203
 204 The \arg{name} should be just the base name of the renderer and not the full
 205 name of the DLL file which is constructed differently (using
 206 \helpref{wxDynamicLibrary::CanonicalizePluginName}{wxdynamiclibrarycanonicalizepluginname})
 207 on different systems.
 208
 209
 210 \membersection{wxRendererNative::Set}\label{wxrenderernativeset}
 211
 212 \func{wxRendererNative*}{Set}{\param{wxRendererNative* }{renderer}}
 213
 214 Set the renderer to use, passing {\tt NULL} reverts to using the default
 215 renderer (the global renderer must always exist).
 216
 217 Return the previous renderer used with Set() or {\tt NULL} if none.
 218