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_SIZE_NORMAL = 0x00000100,
  78     wxCONTROL_SIZE_LARGE  = 0x00000200,
  79     wxCONTROL_SIZE_SMALL  = 0x00000400,
  80     wxCONTROL_SIZE_MINI   = 0x00000800,
  81     wxCONTROL_UNDETERMINED = wxCONTROL_CHECKABLE  // (check) undetermined state
  82 };
  83 \end{verbatim}
  84
  85 \wxheading{Derived from}
  86
  87 No base class
  88
  89 \wxheading{Include files}
  90
  91 <wx/renderer.h>
  92
  93
  94 \latexignore{\rtfignore{\wxheading{Members}}}
  95
  96
  97 \membersection{wxRendererNative::\destruct{wxRendererNative}}\label{wxrenderernativedtor}
  98
  99 \func{}{\destruct{wxRendererNative}}{\void}
 100
 101 Virtual destructor as for any base class.
 102
 103
 104 \membersection{wxRendererNative::DrawCheckBox}\label{wxrenderernativedrawcheckbox}
 105
 106 \func{void}{DrawCheckBox}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 107
 108 Draw a check box (used by wxDataViewCtrl).
 109
 110 \arg{flags} may have the \texttt{wxCONTROL\_CHECKED}, \texttt{wxCONTROL\_CURRENT} or
 111 \texttt{wxCONTROL\_UNDETERMINED} bit set.
 112
 113
 114 \membersection{wxRendererNative::DrawComboBoxDropButton}\label{wxrenderernativedrawcomboboxdropbutton}
 115
 116 \func{void}{DrawComboBoxDropButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 117
 118 Draw a button like the one used by \helpref{wxComboBox}{wxcombobox} to show a
 119 drop down window. The usual appearance is a downwards pointing arrow.
 120
 121 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 122
 123
 124 \membersection{wxRendererNative::DrawDropArrow}\label{wxrenderernativedrawdroparrow}
 125
 126 \func{void}{DrawDropArrow}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 127
 128 Draw a drop down arrow that is suitable for use outside a combo box. Arrow will have
 129 transparent background.
 130
 131 \arg{rect} is not entirely filled by the arrow. Instead, you should use bounding
 132 rectangle of a drop down button which arrow matches the size you need.
 133 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED} or \texttt{wxCONTROL\_CURRENT} bit set.
 134
 135
 136 \membersection{wxRendererNative::DrawHeaderButton}\label{wxrenderernativedrawheaderbutton}
 137
 138 \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}}
 139
 140 Draw the header control button (used, for example, by
 141 \helpref{wxListCtrl}{wxlistctrl}).  Depending on platforms the
 142 \arg{flags} parameter may support the \texttt{wxCONTROL\_SELECTED}
 143 \texttt{wxCONTROL\_DISABLED} and \texttt{wxCONTROL\_CURRENT} bits.
 144 The \arg{sortArrow} parameter can be one of
 145 \texttt{wxHDR\_SORT\_ICON\_NONE}, \texttt{wxHDR\_SORT\_ICON\_UP}, or
 146 \texttt{wxHDR\_SORT\_ICON\_DOWN}.  Additional values controlling the
 147 drawing of a text or bitmap label can be passed in \arg{params}.  The
 148 value returned is the optimal width to contain the the unabreviated
 149 label text or bitmap, the sort arrow if present, and internal margins.
 150
 151
 152
 153 \membersection{wxRendererNative::DrawItemSelectionRect}\label{wxrenderernativedrawitemselectionrect}
 154
 155 \func{void}{DrawItemSelectionRect}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 156
 157 Draw a selection rectangle underneath the text as used e.g. in a
 158 \helpref{wxListCtrl}{wxlistctrl}. The supported \arg{flags} are
 159 \texttt{wxCONTROL\_SELECTED} for items which are selected (e.g. often a blue
 160 rectangle) and \texttt{wxCONTROL\_CURRENT} for the item that has the focus
 161 (often a dotted line around the item's text). \texttt{wxCONTROL\_FOCUSED} may
 162 be used to indicate if the control has the focus (othewise the the selection
 163 rectangle is e.g. often grey and not blue). This may be ignored by the renderer
 164 or deduced by the code directly from the \arg{win}.
 165
 166
 167 \membersection{wxRendererNative::DrawPushButton}\label{wxrenderernativedrawpushbutton}
 168
 169 \func{void}{DrawPushButton}{\param{wxWindow *}{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags}}
 170
 171 Draw a blank push button that looks very similar to \helpref{wxButton}{wxbutton}.
 172
 173 \arg{flags} may have the \texttt{wxCONTROL\_PRESSED}, \texttt{wxCONTROL\_CURRENT} or
 174 \texttt{wxCONTROL\_ISDEFAULT} bit set.
 175
 176
 177 \membersection{wxRendererNative::DrawSplitterBorder}\label{wxrenderernativedrawsplitterborder}
 178
 179 \func{void}{DrawSplitterBorder}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 180
 181 Draw the border for sash window: this border must be such that the sash
 182 drawn by \helpref{DrawSash}{wxrenderernativedrawsplittersash} blends into it
 183 well.
 184
 185
 186 \membersection{wxRendererNative::DrawSplitterSash}\label{wxrenderernativedrawsplittersash}
 187
 188 \func{void}{DrawSplitterSash}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxSize\& }{size}, \param{wxCoord }{position}, \param{wxOrientation }{orient}, \param{int }{flags = 0}}
 189
 190 Draw a sash. The \arg{orient} parameter defines whether the sash should be
 191 vertical or horizontal and how the \arg{position} should be interpreted.
 192
 193
 194 \membersection{wxRendererNative::DrawTreeItemButton}\label{wxrenderernativedrawtreeitembutton}
 195
 196 \func{void}{DrawTreeItemButton}{\param{wxWindow* }{win}, \param{wxDC\& }{dc}, \param{const wxRect\& }{rect}, \param{int }{flags = 0}}
 197
 198 Draw the expanded/collapsed icon for a tree control item. To draw an expanded
 199 button the \arg{flags} parameter must contain {\tt wxCONTROL\_EXPANDED} bit.
 200
 201
 202 \membersection{wxRendererNative::Get}\label{wxrenderernativeget}
 203
 204 \func{wxRendererNative\&}{Get}{\void}
 205
 206 Return the currently used renderer.
 207
 208
 209 \membersection{wxRendererNative::GetDefault}\label{wxrenderernativegetdefault}
 210
 211 \func{wxRendererNative\&}{GetDefault}{\void}
 212
 213 Return the default (native) implementation for this platform -- this is also
 214 the one used by default but this may be changed by calling
 215 \helpref{Set}{wxrenderernativeset} in which case the return value of this
 216 method may be different from the return value of \helpref{Get}{wxrenderernativeget}.
 217
 218
 219 \membersection{wxRendererNative::GetGeneric}\label{wxrenderernativegetgeneric}
 220
 221 \func{wxRendererNative\&}{GetGeneric}{\void}
 222
 223 Return the generic implementation of the renderer. Under some platforms, this
 224 is the default renderer implementation, others have platform-specific default
 225 renderer which can be retrieved by calling \helpref{GetDefault}{wxrenderernativegetdefault}.
 226
 227
 228 \membersection{wxRendererNative::GetHeaderButtonHeight}\label{wxrenderernativegetheaderbuttonheight}
 229
 230 \func{int}{GetHeaderButtonHeight}{\param{const wxWindow* }{win}}
 231
 232 Returns the height of a header button, either a fixed platform height if available, or a
 233 generic height based on the window's font.
 234
 235
 236 \membersection{wxRendererNative::GetSplitterParams}\label{wxrenderernativegetsplitterparams}
 237
 238 \func{wxSplitterRenderParams}{GetSplitterParams}{\param{const wxWindow* }{win}}
 239
 240 Get the splitter parameters, see
 241 \helpref{wxSplitterRenderParams}{wxsplitterrenderparams}.
 242
 243
 244 \membersection{wxRendererNative::GetVersion}\label{wxrenderernativegetversion}
 245
 246 \constfunc{wxRendererVersion}{GetVersion}{\void}
 247
 248 This function is used for version checking: \helpref{Load}{wxrenderernativeload}
 249 refuses to load any shared libraries implementing an older or incompatible
 250 version.
 251
 252 The implementation of this method is always the same in all renderers (simply
 253 construct \helpref{wxRendererVersion}{wxrendererversion} using the
 254 {\tt wxRendererVersion::Current\_XXX} values), but it has to be in the derived,
 255 not base, class, to detect mismatches between the renderers versions and so you
 256 have to implement it anew in all renderers.
 257
 258
 259 \membersection{wxRendererNative::Load}\label{wxrenderernativeload}
 260
 261 \func{wxRendererNative*}{Load}{\param{const wxString\& }{name}}
 262
 263 Load the renderer from the specified DLL, the returned pointer must be
 264 deleted by caller if not {\tt NULL} when it is not used any more.
 265
 266 The \arg{name} should be just the base name of the renderer and not the full
 267 name of the DLL file which is constructed differently (using
 268 \helpref{wxDynamicLibrary::CanonicalizePluginName}{wxdynamiclibrarycanonicalizepluginname})
 269 on different systems.
 270
 271
 272 \membersection{wxRendererNative::Set}\label{wxrenderernativeset}
 273
 274 \func{wxRendererNative*}{Set}{\param{wxRendererNative* }{renderer}}
 275
 276 Set the renderer to use, passing {\tt NULL} reverts to using the default
 277 renderer (the global renderer must always exist).
 278
 279 Return the previous renderer used with Set() or {\tt NULL} if none.
 280