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