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{int}{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}.  The
 144 value returned is the optimal width to contain the the unabreviated
 145 label text or bitmap, the sort arrow if present, and internal margins.
 146
 147
 148
 149 \membersection{wxRendererNative::DrawItemSelectionRect}\label{wxrenderernativedrawitemselectionrect}
 150
 151 \func{void}{DrawItemSelectionRect}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 152
 153 Draw a selection rectangle underneath the text as used e.g. in a
 154 \helpref{wxListCtrl}{wxlistctrl}. The supported \arg{flags} are
 155 \texttt{wxCONTROL\_SELECTED} for items which are selected (e.g. often a blue
 156 rectangle) and \texttt{wxCONTROL\_CURRENT} for the item that has the focus
 157 (often a dotted line around the item's text). \texttt{wxCONTROL\_FOCUSED} may
 158 be used to indicate if the control has the focus (othewise the the selection
 159 rectangle is e.g. often grey and not blue). This may be ignored by the renderer
 160 or deduced by the code directly from the \arg{win}.
 161
 162
 163 \membersection{wxRendererNative::DrawPushButton}\label{wxrenderernativedrawpushbutton}
 164
 165 \func{void}{DrawPushButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 166
 167 Draw a blank push button that looks very similar to \helpref{wxButton}{wxbutton}.
 168
 169 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED}, \texttt{wxCONTROL\_CURRENT} or
 170 \texttt{wxCONTROL\_ISDEFAULT} bit set.
 171
 172
 173 \membersection{wxRendererNative::DrawSplitterBorder}\label{wxrenderernativedrawsplitterborder}
 174
 175 \func{void}{DrawSplitterBorder}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 176
 177 Draw the border for sash window: this border must be such that the sash
 178 drawn by \helpref{DrawSash}{wxrenderernativedrawsplittersash} blends into it
 179 well.
 180
 181
 182 \membersection{wxRendererNative::DrawSplitterSash}\label{wxrenderernativedrawsplittersash}
 183
 184 \func{void}{DrawSplitterSash}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxSize\& }{size}, \param{wxCoord }{position}, \param{wxOrientation }{orient}, \param{int }{flags = 0}}
 185
 186 Draw a sash. The \arg{orient} parameter defines whether the sash should be
 187 vertical or horizontal and how the \arg{position} should be interpreted.
 188
 189
 190 \membersection{wxRendererNative::DrawTreeItemButton}\label{wxrenderernativedrawtreeitembutton}
 191
 192 \func{void}{DrawTreeItemButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 193
 194 Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 195 button the \arg{flags} parameter must contain {\tt wxCONTROL\_EXPANDED} bit.
 196
 197
 198 \membersection{wxRendererNative::Get}\label{wxrenderernativeget}
 199
 200 \func{wxRendererNative\&}{Get}{\void}
 201
 202 Return the currently used renderer.
 203
 204
 205 \membersection{wxRendererNative::GetDefault}\label{wxrenderernativegetdefault}
 206
 207 \func{wxRendererNative\&}{GetDefault}{\void}
 208
 209 Return the default (native) implementation for this platform -- this is also
 210 the one used by default but this may be changed by calling
 211 \helpref{Set}{wxrenderernativeset} in which case the return value of this
 212 method may be different from the return value of \helpref{Get}{wxrenderernativeget}.
 213
 214
 215 \membersection{wxRendererNative::GetGeneric}\label{wxrenderernativegetgeneric}
 216
 217 \func{wxRendererNative\&}{GetGeneric}{\void}
 218
 219 Return the generic implementation of the renderer. Under some platforms, this
 220 is the default renderer implementation, others have platform-specific default
 221 renderer which can be retrieved by calling \helpref{GetDefault}{wxrenderernativegetdefault}.
 222
 223
 224 \membersection{wxRendererNative::GetHeaderButtonHeight}\label{wxrenderernativegetheaderbuttonheight}
 225
 226 \func{int}{GetHeaderButtonHeight}{\param{const wxWindow* }{win}}
 227
 228 Returns the height of a header button, either a fixed platform height if available, or a
 229 generic height based on the window's font.
 230
 231
 232 \membersection{wxRendererNative::GetSplitterParams}\label{wxrenderernativegetsplitterparams}
 233
 234 \func{wxSplitterRenderParams}{GetSplitterParams}{\param{const wxWindow* }{win}}
 235
 236 Get the splitter parameters, see
 237 \helpref{wxSplitterRenderParams}{wxsplitterrenderparams}.
 238
 239
 240 \membersection{wxRendererNative::GetVersion}\label{wxrenderernativegetversion}
 241
 242 \constfunc{wxRendererVersion}{GetVersion}{\void}
 243
 244 This function is used for version checking: \helpref{Load}{wxrenderernativeload}
 245 refuses to load any shared libraries implementing an older or incompatible
 246 version.
 247
 248 The implementation of this method is always the same in all renderers (simply
 249 construct \helpref{wxRendererVersion}{wxrendererversion} using the
 250 {\tt wxRendererVersion::Current\_XXX} values), but it has to be in the derived,
 251 not base, class, to detect mismatches between the renderers versions and so you
 252 have to implement it anew in all renderers.
 253
 254
 255 \membersection{wxRendererNative::Load}\label{wxrenderernativeload}
 256
 257 \func{wxRendererNative*}{Load}{\param{const wxString\& }{name}}
 258
 259 Load the renderer from the specified DLL, the returned pointer must be
 260 deleted by caller if not {\tt NULL} when it is not used any more.
 261
 262 The \arg{name} should be just the base name of the renderer and not the full
 263 name of the DLL file which is constructed differently (using
 264 \helpref{wxDynamicLibrary::CanonicalizePluginName}{wxdynamiclibrarycanonicalizepluginname})
 265 on different systems.
 266
 267
 268 \membersection{wxRendererNative::Set}\label{wxrenderernativeset}
 269
 270 \func{wxRendererNative*}{Set}{\param{wxRendererNative* }{renderer}}
 271
 272 Set the renderer to use, passing {\tt NULL} reverts to using the default
 273 renderer (the global renderer must always exist).
 274
 275 Return the previous renderer used with Set() or {\tt NULL} if none.
 276