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_SPECIAL    = 0x00000008,  // control-specific bit:
  71     wxCONTROL_ISDEFAULT  = wxCONTROL_SPECIAL, // only for the buttons
  72     wxCONTROL_ISSUBMENU  = wxCONTROL_SPECIAL, // only for the menu items
  73     wxCONTROL_EXPANDED   = wxCONTROL_SPECIAL, // only for the tree items
  74     wxCONTROL_SIZEGRIP   = wxCONTROL_SPECIAL, // only for the status bar panes
  75     wxCONTROL_FLAT       = wxCONTROL_SPECIAL, // checkboxes only: flat border
  76     wxCONTROL_CURRENT    = 0x00000010,  // mouse is currently over the control
  77     wxCONTROL_SELECTED   = 0x00000020,  // selected item in e.g. listbox
  78     wxCONTROL_CHECKED    = 0x00000040,  // (check/radio button) is checked
  79     wxCONTROL_CHECKABLE  = 0x00000080,  // (menu) item can be checked
  80     wxCONTROL_UNDETERMINED = wxCONTROL_CHECKABLE  // (check) undetermined state
  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 \wxheading{Library}
  93
  94 \helpref{wxCore}{librarieslist}
  95
  96
  97 \latexignore{\rtfignore{\wxheading{Members}}}
  98
  99
 100 \membersection{wxRendererNative::\destruct{wxRendererNative}}\label{wxrenderernativedtor}
 101
 102 \func{}{\destruct{wxRendererNative}}{\void}
 103
 104 Virtual destructor as for any base class.
 105
 106
 107 \membersection{wxRendererNative::DrawCheckBox}\label{wxrenderernativedrawcheckbox}
 108
 109 \func{void}{DrawCheckBox}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 110
 111 Draw a check box (used by wxDataViewCtrl).
 112
 113 \arg{flags} may have the \texttt{wxCONTROL\_CHECKED}, \texttt{wxCONTROL\_CURRENT} or
 114 \texttt{wxCONTROL\_UNDETERMINED} bit set.
 115
 116
 117 \membersection{wxRendererNative::DrawComboBoxDropButton}\label{wxrenderernativedrawcomboboxdropbutton}
 118
 119 \func{void}{DrawComboBoxDropButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 120
 121 Draw a button like the one used by \helpref{wxComboBox}{wxcombobox} to show a
 122 drop down window. The usual appearance is a downwards pointing arrow.
 123
 124 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 125
 126
 127 \membersection{wxRendererNative::DrawDropArrow}\label{wxrenderernativedrawdroparrow}
 128
 129 \func{void}{DrawDropArrow}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 130
 131 Draw a drop down arrow that is suitable for use outside a combo box. Arrow will have
 132 transparent background.
 133
 134 \arg{rect} is not entirely filled by the arrow. Instead, you should use bounding
 135 rectangle of a drop down button which arrow matches the size you need.
 136 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 137
 138
 139 \membersection{wxRendererNative::DrawHeaderButton}\label{wxrenderernativedrawheaderbutton}
 140
 141 \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}}
 142
 143 Draw the header control button (used, for example, by
 144 \helpref{wxListCtrl}{wxlistctrl}).  Depending on platforms the
 145 \arg{flags} parameter may support the \texttt{wxCONTROL\_SELECTED}
 146 \texttt{wxCONTROL\_DISABLED} and \texttt{wxCONTROL\_CURRENT} bits.
 147 The \arg{sortArrow} parameter can be one of
 148 \texttt{wxHDR\_SORT\_ICON\_NONE}, \texttt{wxHDR\_SORT\_ICON\_UP}, or
 149 \texttt{wxHDR\_SORT\_ICON\_DOWN}.  Additional values controlling the
 150 drawing of a text or bitmap label can be passed in \arg{params}.  The
 151 value returned is the optimal width to contain the the unabreviated
 152 label text or bitmap, the sort arrow if present, and internal margins.
 153
 154
 155
 156 \membersection{wxRendererNative::DrawItemSelectionRect}\label{wxrenderernativedrawitemselectionrect}
 157
 158 \func{void}{DrawItemSelectionRect}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 159
 160 Draw a selection rectangle underneath the text as used e.g. in a
 161 \helpref{wxListCtrl}{wxlistctrl}. The supported \arg{flags} are
 162 \texttt{wxCONTROL\_SELECTED} for items which are selected (e.g. often a blue
 163 rectangle) and \texttt{wxCONTROL\_CURRENT} for the item that has the focus
 164 (often a dotted line around the item's text). \texttt{wxCONTROL\_FOCUSED} may
 165 be used to indicate if the control has the focus (othewise the the selection
 166 rectangle is e.g. often grey and not blue). This may be ignored by the renderer
 167 or deduced by the code directly from the \arg{win}.
 168
 169
 170 \membersection{wxRendererNative::DrawPushButton}\label{wxrenderernativedrawpushbutton}
 171
 172 \func{void}{DrawPushButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 173
 174 Draw a blank push button that looks very similar to \helpref{wxButton}{wxbutton}.
 175
 176 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED}, \texttt{wxCONTROL\_CURRENT} or
 177 \texttt{wxCONTROL\_ISDEFAULT} bit set.
 178
 179
 180 \membersection{wxRendererNative::DrawSplitterBorder}\label{wxrenderernativedrawsplitterborder}
 181
 182 \func{void}{DrawSplitterBorder}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 183
 184 Draw the border for sash window: this border must be such that the sash
 185 drawn by \helpref{DrawSash}{wxrenderernativedrawsplittersash} blends into it
 186 well.
 187
 188
 189 \membersection{wxRendererNative::DrawSplitterSash}\label{wxrenderernativedrawsplittersash}
 190
 191 \func{void}{DrawSplitterSash}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxSize\& }{size}, \param{wxCoord }{position}, \param{wxOrientation }{orient}, \param{int }{flags = 0}}
 192
 193 Draw a sash. The \arg{orient} parameter defines whether the sash should be
 194 vertical or horizontal and how the \arg{position} should be interpreted.
 195
 196
 197 \membersection{wxRendererNative::DrawTreeItemButton}\label{wxrenderernativedrawtreeitembutton}
 198
 199 \func{void}{DrawTreeItemButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 200
 201 Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 202 button the \arg{flags} parameter must contain {\tt wxCONTROL\_EXPANDED} bit.
 203
 204
 205 \membersection{wxRendererNative::Get}\label{wxrenderernativeget}
 206
 207 \func{wxRendererNative\&}{Get}{\void}
 208
 209 Return the currently used renderer.
 210
 211
 212 \membersection{wxRendererNative::GetDefault}\label{wxrenderernativegetdefault}
 213
 214 \func{wxRendererNative\&}{GetDefault}{\void}
 215
 216 Return the default (native) implementation for this platform -- this is also
 217 the one used by default but this may be changed by calling
 218 \helpref{Set}{wxrenderernativeset} in which case the return value of this
 219 method may be different from the return value of \helpref{Get}{wxrenderernativeget}.
 220
 221
 222 \membersection{wxRendererNative::GetGeneric}\label{wxrenderernativegetgeneric}
 223
 224 \func{wxRendererNative\&}{GetGeneric}{\void}
 225
 226 Return the generic implementation of the renderer. Under some platforms, this
 227 is the default renderer implementation, others have platform-specific default
 228 renderer which can be retrieved by calling \helpref{GetDefault}{wxrenderernativegetdefault}.
 229
 230
 231 \membersection{wxRendererNative::GetHeaderButtonHeight}\label{wxrenderernativegetheaderbuttonheight}
 232
 233 \func{int}{GetHeaderButtonHeight}{\param{const wxWindow* }{win}}
 234
 235 Returns the height of a header button, either a fixed platform height if available, or a
 236 generic height based on the window's font.
 237
 238
 239 \membersection{wxRendererNative::GetSplitterParams}\label{wxrenderernativegetsplitterparams}
 240
 241 \func{wxSplitterRenderParams}{GetSplitterParams}{\param{const wxWindow* }{win}}
 242
 243 Get the splitter parameters, see
 244 \helpref{wxSplitterRenderParams}{wxsplitterrenderparams}.
 245
 246
 247 \membersection{wxRendererNative::GetVersion}\label{wxrenderernativegetversion}
 248
 249 \constfunc{wxRendererVersion}{GetVersion}{\void}
 250
 251 This function is used for version checking: \helpref{Load}{wxrenderernativeload}
 252 refuses to load any shared libraries implementing an older or incompatible
 253 version.
 254
 255 The implementation of this method is always the same in all renderers (simply
 256 construct \helpref{wxRendererVersion}{wxrendererversion} using the
 257 {\tt wxRendererVersion::Current\_XXX} values), but it has to be in the derived,
 258 not base, class, to detect mismatches between the renderers versions and so you
 259 have to implement it anew in all renderers.
 260
 261
 262 \membersection{wxRendererNative::Load}\label{wxrenderernativeload}
 263
 264 \func{wxRendererNative*}{Load}{\param{const wxString\& }{name}}
 265
 266 Load the renderer from the specified DLL, the returned pointer must be
 267 deleted by caller if not {\tt NULL} when it is not used any more.
 268
 269 The \arg{name} should be just the base name of the renderer and not the full
 270 name of the DLL file which is constructed differently (using
 271 \helpref{wxDynamicLibrary::CanonicalizePluginName}{wxdynamiclibrarycanonicalizepluginname})
 272 on different systems.
 273
 274
 275 \membersection{wxRendererNative::Set}\label{wxrenderernativeset}
 276
 277 \func{wxRendererNative*}{Set}{\param{wxRendererNative* }{renderer}}
 278
 279 Set the renderer to use, passing {\tt NULL} reverts to using the default
 280 renderer (the global renderer must always exist).
 281
 282 Return the previous renderer used with Set() or {\tt NULL} if none.
 283