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 };
  79 \end{verbatim}
  80
  81 \wxheading{Derived from}
  82
  83 No base class
  84
  85 \wxheading{Include files}
  86
  87 <wx/renderer.h>
  88
  89
  90 \latexignore{\rtfignore{\wxheading{Members}}}
  91
  92
  93 \membersection{wxRendererNative::\destruct{wxRendererNative}}\label{wxrenderernativedtor}
  94
  95 \func{}{\destruct{wxRendererNative}}{\void}
  96
  97 Virtual destructor as for any base class.
  98
  99
 100 \membersection{wxRendererNative::DrawCheckBox}\label{wxrenderernativedrawcheckbox}
 101
 102 \func{void}{DrawCheckBox}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 103
 104 Draw a check box (used by wxDataViewCtrl).
 105
 106 \arg{flags} may have the \texttt{wxCONTROL\_CHECKED}, \texttt{wxCONTROL\_CURRENT} or
 107 \texttt{wxCONTROL\_UNDETERMINED} bit set.
 108
 109
 110 \membersection{wxRendererNative::DrawComboBoxDropButton}\label{wxrenderernativedrawcomboboxdropbutton}
 111
 112 \func{void}{DrawComboBoxDropButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 113
 114 Draw a button like the one used by \helpref{wxComboBox}{wxcombobox} to show a
 115 drop down window. The usual appearance is a downwards pointing arrow.
 116
 117 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 118
 119
 120 \membersection{wxRendererNative::DrawDropArrow}\label{wxrenderernativedrawdroparrow}
 121
 122 \func{void}{DrawDropArrow}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 123
 124 Draw a drop down arrow that is suitable for use outside a combo box. Arrow will have
 125 transparent background.
 126
 127 \arg{rect} is not entirely filled by the arrow. Instead, you should use bounding
 128 rectangle of a drop down button which arrow matches the size you need.
 129 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 130
 131
 132 \membersection{wxRendererNative::DrawHeaderButton}\label{wxrenderernativedrawheaderbutton}
 133
 134 \func{void}{DrawHeaderButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}, \param{wxHeaderSortIconType }{sortArrow = wxHDR\_SORT\_ICON\_NONE}, \param{wxHeaderButtonParams* }{params = NULL}}
 135
 136 Draw the header control button (used, for example, by
 137 \helpref{wxListCtrl}{wxlistctrl}).  Depending on platforms the
 138 \arg{flags} parameter may support the \texttt{wxCONTROL\_SELECTED}
 139 \texttt{wxCONTROL\_DISABLED} and \texttt{wxCONTROL\_CURRENT} bits.
 140 The \arg{sortArrow} parameter can be one of
 141 \texttt{wxHDR\_SORT\_ICON\_NONE}, \texttt{wxHDR\_SORT\_ICON\_UP}, or
 142 \texttt{wxHDR\_SORT\_ICON\_DOWN}.  Additional values controlling the
 143 drawing of a text or bitmap label can be passed in \arg{params}.
 144
 145
 146 \membersection{wxRendererNative::DrawItemSelectionRect}\label{wxrenderernativedrawitemselectionrect}
 147
 148 \func{void}{DrawItemSelectionRect}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 149
 150 Draw a selection rectangle underneath the text as used e.g. in a
 151 \helpref{wxListCtrl}{wxlistctrl}. The supported \arg{flags} are
 152 \texttt{wxCONTROL\_SELECTED} for items which are selected (e.g. often a blue
 153 rectangle) and \texttt{wxCONTROL\_CURRENT} for the item that has the focus
 154 (often a dotted line around the item's text). \texttt{wxCONTROL\_FOCUSED} may
 155 be used to indicate if the control has the focus (othewise the the selection
 156 rectangle is e.g. often grey and not blue). This may be ignored by the renderer
 157 or deduced by the code directly from the \arg{win}.
 158
 159
 160 \membersection{wxRendererNative::DrawPushButton}\label{wxrenderernativedrawpushbutton}
 161
 162 \func{void}{DrawPushButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 163
 164 Draw a blank push button that looks very similar to \helpref{wxButton}{wxbutton}.
 165
 166 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED}, \texttt{wxCONTROL\_CURRENT} or
 167 \texttt{wxCONTROL\_ISDEFAULT} bit set.
 168
 169
 170 \membersection{wxRendererNative::DrawSplitterBorder}\label{wxrenderernativedrawsplitterborder}
 171
 172 \func{void}{DrawSplitterBorder}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 173
 174 Draw the border for sash window: this border must be such that the sash
 175 drawn by \helpref{DrawSash}{wxrenderernativedrawsplittersash} blends into it
 176 well.
 177
 178
 179 \membersection{wxRendererNative::DrawSplitterSash}\label{wxrenderernativedrawsplittersash}
 180
 181 \func{void}{DrawSplitterSash}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxSize\& }{size}, \param{wxCoord }{position}, \param{wxOrientation }{orient}, \param{int }{flags = 0}}
 182
 183 Draw a sash. The \arg{orient} parameter defines whether the sash should be
 184 vertical or horizontal and how the \arg{position} should be interpreted.
 185
 186
 187 \membersection{wxRendererNative::DrawTreeItemButton}\label{wxrenderernativedrawtreeitembutton}
 188
 189 \func{void}{DrawTreeItemButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 190
 191 Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 192 button the \arg{flags} parameter must contain {\tt wxCONTROL\_EXPANDED} bit.
 193
 194
 195 \membersection{wxRendererNative::Get}\label{wxrenderernativeget}
 196
 197 \func{wxRendererNative\&}{Get}{\void}
 198
 199 Return the currently used renderer.
 200
 201
 202 \membersection{wxRendererNative::GetDefault}\label{wxrenderernativegetdefault}
 203
 204 \func{wxRendererNative\&}{GetDefault}{\void}
 205
 206 Return the default (native) implementation for this platform -- this is also
 207 the one used by default but this may be changed by calling
 208 \helpref{Set}{wxrenderernativeset} in which case the return value of this
 209 method may be different from the return value of \helpref{Get}{wxrenderernativeget}.
 210
 211
 212 \membersection{wxRendererNative::GetGeneric}\label{wxrenderernativegetgeneric}
 213
 214 \func{wxRendererNative\&}{GetGeneric}{\void}
 215
 216 Return the generic implementation of the renderer. Under some platforms, this
 217 is the default renderer implementation, others have platform-specific default
 218 renderer which can be retrieved by calling \helpref{GetDefault}{wxrenderernativegetdefault}.
 219
 220
 221 \membersection{wxRendererNative::GetHeaderButtonHeight}\label{wxrenderernativegetheaderbuttonheight}
 222
 223 \func{int}{GetHeaderButtonHeight}{\param{const wxWindow* }{win}}
 224
 225 Returns the height of a header button, either a fixed platform height if available, or a
 226 generic height based on the window's font.
 227
 228
 229 \membersection{wxRendererNative::GetSplitterParams}\label{wxrenderernativegetsplitterparams}
 230
 231 \func{wxSplitterRenderParams}{GetSplitterParams}{\param{const wxWindow* }{win}}
 232
 233 Get the splitter parameters, see
 234 \helpref{wxSplitterRenderParams}{wxsplitterrenderparams}.
 235
 236
 237 \membersection{wxRendererNative::GetVersion}\label{wxrenderernativegetversion}
 238
 239 \constfunc{wxRendererVersion}{GetVersion}{\void}
 240
 241 This function is used for version checking: \helpref{Load}{wxrenderernativeload}
 242 refuses to load any shared libraries implementing an older or incompatible
 243 version.
 244
 245 The implementation of this method is always the same in all renderers (simply
 246 construct \helpref{wxRendererVersion}{wxrendererversion} using the
 247 {\tt wxRendererVersion::Current\_XXX} values), but it has to be in the derived,
 248 not base, class, to detect mismatches between the renderers versions and so you
 249 have to implement it anew in all renderers.
 250
 251
 252 \membersection{wxRendererNative::Load}\label{wxrenderernativeload}
 253
 254 \func{wxRendererNative*}{Load}{\param{const wxString\& }{name}}
 255
 256 Load the renderer from the specified DLL, the returned pointer must be
 257 deleted by caller if not {\tt NULL} when it is not used any more.
 258
 259 The \arg{name} should be just the base name of the renderer and not the full
 260 name of the DLL file which is constructed differently (using
 261 \helpref{wxDynamicLibrary::CanonicalizePluginName}{wxdynamiclibrarycanonicalizepluginname})
 262 on different systems.
 263
 264
 265 \membersection{wxRendererNative::Set}\label{wxrenderernativeset}
 266
 267 \func{wxRendererNative*}{Set}{\param{wxRendererNative* }{renderer}}
 268
 269 Set the renderer to use, passing {\tt NULL} reverts to using the default
 270 renderer (the global renderer must always exist).
 271
 272 Return the previous renderer used with Set() or {\tt NULL} if none.
 273