docs/latex/wx/brush.tex

   1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2 %% Name:        brush.tex
   3 %% Purpose:     wxPen docs
   4 %% Author:
   5 %% Modified by:
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   7 %% RCS-ID:      $Id$
   8 %% Copyright:   (c) wxWidgets
   9 %% License:     wxWindows license
  10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  11
  12 \section{\class{wxBrush}}\label{wxbrush}
  13
  14 A brush is a drawing tool for filling in areas. It is used for painting
  15 the background of rectangles, ellipses, etc. It has a colour and a
  16 style.
  17
  18 \wxheading{Derived from}
  19
  20 \helpref{wxGDIObject}{wxgdiobject}\\
  21 \helpref{wxObject}{wxobject}
  22
  23 \wxheading{Include files}
  24
  25 <wx/brush.h>
  26
  27 \wxheading{Predefined objects}
  28
  29 Objects:
  30
  31 {\bf wxNullBrush}
  32
  33 Pointers:
  34
  35 {\bf wxBLUE\_BRUSH\\
  36 wxGREEN\_BRUSH\\
  37 wxWHITE\_BRUSH\\
  38 wxBLACK\_BRUSH\\
  39 wxGREY\_BRUSH\\
  40 wxMEDIUM\_GREY\_BRUSH\\
  41 wxLIGHT\_GREY\_BRUSH\\
  42 wxTRANSPARENT\_BRUSH\\
  43 wxCYAN\_BRUSH\\
  44 wxRED\_BRUSH}
  45
  46 \wxheading{Remarks}
  47
  48 On a monochrome display, wxWidgets shows
  49 all brushes as white unless the colour is really black.
  50
  51 Do not initialize objects on the stack before the program commences,
  52 since other required structures may not have been set up yet. Instead,
  53 define global pointers to objects and create them in \helpref{wxApp::OnInit}{wxapponinit} or
  54 when required.
  55
  56 An application may wish to create brushes with different
  57 characteristics dynamically, and there is the consequent danger that a
  58 large number of duplicate brushes will be created. Therefore an
  59 application may wish to get a pointer to a brush by using the global
  60 list of brushes {\bf wxTheBrushList}, and calling the member function
  61 \rtfsp{\bf FindOrCreateBrush}.
  62
  63 wxBrush uses a reference counting system, so assignments between brushes are very
  64 cheap. You can therefore use actual wxBrush objects instead of pointers without
  65 efficiency problems. Once one wxBrush object changes its data it will create its
  66 own brush data internally so that other brushes, which previously shared the
  67 data using the reference counting, are not affected.
  68
  69 %TODO: an overview for wxBrush.
  70 \wxheading{See also}
  71
  72 \helpref{wxBrushList}{wxbrushlist}, \helpref{wxDC}{wxdc}, \helpref{wxDC::SetBrush}{wxdcsetbrush}
  73
  74 \latexignore{\rtfignore{\wxheading{Members}}}
  75
  76
  77 \membersection{wxBrush::wxBrush}\label{wxbrushctor}
  78
  79 \func{}{wxBrush}{\void}
  80
  81 Default constructor. The brush will be uninitialised, and \helpref{wxBrush:IsOk}{wxbrushisok} will
  82 return false.
  83
  84 \func{}{wxBrush}{\param{const wxColour\&}{ colour}, \param{int}{ style = {\tt wxSOLID}}}
  85
  86 Constructs a brush from a colour object and style.
  87
  88 \func{}{wxBrush}{\param{const wxString\& }{colourName}, \param{int}{ style}}
  89
  90 Constructs a brush from a colour name and style.
  91
  92 \func{}{wxBrush}{\param{const wxBitmap\& }{stippleBitmap}}
  93
  94 Constructs a stippled brush using a bitmap.
  95
  96 \func{}{wxBrush}{\param{const wxBrush\&}{ brush}}
  97
  98 Copy constructor, uses \helpref{reference counting}{trefcount}.
  99
 100 \wxheading{Parameters}
 101
 102 \docparam{colour}{Colour object.}
 103
 104 \docparam{colourName}{Colour name. The name will be looked up in the colour database.}
 105
 106 \docparam{style}{One of:
 107
 108 \begin{twocollist}\itemsep=0pt
 109 \twocolitem{{\bf wxTRANSPARENT}}{Transparent (no fill).}
 110 \twocolitem{{\bf wxSOLID}}{Solid.}
 111 \twocolitem{{\bf wxSTIPPLE}}{Uses a bitmap as a stipple.}
 112 \twocolitem{{\bf wxBDIAGONAL\_HATCH}}{Backward diagonal hatch.}
 113 \twocolitem{{\bf wxCROSSDIAG\_HATCH}}{Cross-diagonal hatch.}
 114 \twocolitem{{\bf wxFDIAGONAL\_HATCH}}{Forward diagonal hatch.}
 115 \twocolitem{{\bf wxCROSS\_HATCH}}{Cross hatch.}
 116 \twocolitem{{\bf wxHORIZONTAL\_HATCH}}{Horizontal hatch.}
 117 \twocolitem{{\bf wxVERTICAL\_HATCH}}{Vertical hatch.}
 118 \end{twocollist}}
 119
 120 \docparam{brush}{Pointer or reference to a brush to copy.}
 121
 122 \docparam{stippleBitmap}{A bitmap to use for stippling.}
 123
 124 \wxheading{Remarks}
 125
 126 If a stipple brush is created, the brush style will be set to wxSTIPPLE.
 127
 128 \wxheading{See also}
 129
 130 \helpref{wxBrushList}{wxbrushlist}, \helpref{wxColour}{wxcolour}, \helpref{wxColourDatabase}{wxcolourdatabase}
 131
 132
 133 \membersection{wxBrush::\destruct{wxBrush}}\label{wxbrushdtor}
 134
 135 \func{}{\destruct{wxBrush}}{\void}
 136
 137 Destructor.
 138 See \helpref{reference-counted object destruction}{refcountdestruct} for more info.
 139
 140 \wxheading{Remarks}
 141
 142 Although all remaining brushes are deleted when the application exits,
 143 the application should try to clean up all brushes itself. This is because
 144 wxWidgets cannot know if a pointer to the brush object is stored in an
 145 application data structure, and there is a risk of double deletion.
 146
 147
 148 \membersection{wxBrush::GetColour}\label{wxbrushgetcolour}
 149
 150 \constfunc{wxColour\&}{GetColour}{\void}
 151
 152 Returns a reference to the brush colour.
 153
 154 \wxheading{See also}
 155
 156 \helpref{wxBrush::SetColour}{wxbrushsetcolour}
 157
 158
 159 \membersection{wxBrush::GetStipple}\label{wxbrushgetstipple}
 160
 161 \constfunc{wxBitmap *}{GetStipple}{\void}
 162
 163 Gets a pointer to the stipple bitmap. If the brush does not have a wxSTIPPLE style,
 164 this bitmap may be non-NULL but uninitialised (\helpref{wxBitmap:IsOk}{wxbitmapisok} returns false).
 165
 166 \wxheading{See also}
 167
 168 \helpref{wxBrush::SetStipple}{wxbrushsetstipple}
 169
 170
 171 \membersection{wxBrush::GetStyle}\label{wxbrushgetstyle}
 172
 173 \constfunc{int}{GetStyle}{\void}
 174
 175 Returns the brush style, one of:
 176
 177 \begin{twocollist}\itemsep=0pt
 178 \twocolitem{{\bf wxTRANSPARENT}}{Transparent (no fill).}
 179 \twocolitem{{\bf wxSOLID}}{Solid.}
 180 \twocolitem{{\bf wxBDIAGONAL\_HATCH}}{Backward diagonal hatch.}
 181 \twocolitem{{\bf wxCROSSDIAG\_HATCH}}{Cross-diagonal hatch.}
 182 \twocolitem{{\bf wxFDIAGONAL\_HATCH}}{Forward diagonal hatch.}
 183 \twocolitem{{\bf wxCROSS\_HATCH}}{Cross hatch.}
 184 \twocolitem{{\bf wxHORIZONTAL\_HATCH}}{Horizontal hatch.}
 185 \twocolitem{{\bf wxVERTICAL\_HATCH}}{Vertical hatch.}
 186 \twocolitem{{\bf wxSTIPPLE}}{Stippled using a bitmap.}
 187 \twocolitem{{\bf wxSTIPPLE\_MASK\_OPAQUE}}{Stippled using a bitmap's mask.}
 188 \end{twocollist}
 189
 190 \wxheading{See also}
 191
 192 \helpref{wxBrush::SetStyle}{wxbrushsetstyle}, \helpref{wxBrush::SetColour}{wxbrushsetcolour},\rtfsp
 193 \helpref{wxBrush::SetStipple}{wxbrushsetstipple}
 194
 195
 196 \membersection{wxBrush::IsHatch}\label{wxbrushishatch}
 197
 198 \constfunc{bool}{IsHatch}{\void}
 199
 200 Returns true if the style of the brush is any of hatched fills.
 201
 202 \wxheading{See also}
 203
 204 \helpref{wxBrush::GetStyle}{wxbrushgetstyle}
 205
 206
 207 \membersection{wxBrush::IsOk}\label{wxbrushisok}
 208
 209 \constfunc{bool}{IsOk}{\void}
 210
 211 Returns true if the brush is initialised. It will return false if the default
 212 constructor has been used (for example, the brush is a member of a class, or
 213 NULL has been assigned to it).
 214
 215
 216 \membersection{wxBrush::SetColour}\label{wxbrushsetcolour}
 217
 218 \func{void}{SetColour}{\param{wxColour\& }{colour}}
 219
 220 Sets the brush colour using a reference to a colour object.
 221
 222 \func{void}{SetColour}{\param{const wxString\& }{colourName}}
 223
 224 Sets the brush colour using a colour name from the colour database.
 225
 226 \func{void}{SetColour}{\param{unsigned char}{ red}, \param{unsigned char}{ green}, \param{unsigned char}{ blue}}
 227
 228 Sets the brush colour using red, green and blue values.
 229
 230 \wxheading{See also}
 231
 232 \helpref{wxBrush::GetColour}{wxbrushgetcolour}
 233
 234
 235 \membersection{wxBrush::SetStipple}\label{wxbrushsetstipple}
 236
 237 \func{void}{SetStipple}{\param{const wxBitmap\&}{ bitmap}}
 238
 239 Sets the stipple bitmap.
 240
 241 \wxheading{Parameters}
 242
 243 \docparam{bitmap}{The bitmap to use for stippling.}
 244
 245 \wxheading{Remarks}
 246
 247 The style will be set to wxSTIPPLE, unless the bitmap has a mask associated
 248 to it, in which case the style will be set to wxSTIPPLE\_MASK\_OPAQUE.
 249
 250 If the wxSTIPPLE variant is used, the bitmap will be used to fill out the
 251 area to be drawn. If the wxSTIPPLE\_MASK\_OPAQUE is used, the current
 252 text foreground and text background determine what colours are used for
 253 displaying and the bits in the mask (which is a mono-bitmap actually)
 254 determine where to draw what.
 255
 256 Note that under Windows 95, only 8x8 pixel large stipple bitmaps are
 257 supported, Windows 98 and NT as well as GTK support arbitrary bitmaps.
 258
 259 \wxheading{See also}
 260
 261 \helpref{wxBitmap}{wxbitmap}
 262
 263
 264 \membersection{wxBrush::SetStyle}\label{wxbrushsetstyle}
 265
 266 \func{void}{SetStyle}{\param{int}{ style}}
 267
 268 Sets the brush style.
 269
 270 \docparam{style}{One of:
 271
 272 \begin{twocollist}\itemsep=0pt
 273 \twocolitem{{\bf wxTRANSPARENT}}{Transparent (no fill).}
 274 \twocolitem{{\bf wxSOLID}}{Solid.}
 275 \twocolitem{{\bf wxBDIAGONAL\_HATCH}}{Backward diagonal hatch.}
 276 \twocolitem{{\bf wxCROSSDIAG\_HATCH}}{Cross-diagonal hatch.}
 277 \twocolitem{{\bf wxFDIAGONAL\_HATCH}}{Forward diagonal hatch.}
 278 \twocolitem{{\bf wxCROSS\_HATCH}}{Cross hatch.}
 279 \twocolitem{{\bf wxHORIZONTAL\_HATCH}}{Horizontal hatch.}
 280 \twocolitem{{\bf wxVERTICAL\_HATCH}}{Vertical hatch.}
 281 \twocolitem{{\bf wxSTIPPLE}}{Stippled using a bitmap.}
 282 \twocolitem{{\bf wxSTIPPLE\_MASK\_OPAQUE}}{Stippled using a bitmap's mask.}
 283 \end{twocollist}}
 284
 285 \wxheading{See also}
 286
 287 \helpref{wxBrush::GetStyle}{wxbrushgetstyle}
 288
 289
 290 \membersection{wxBrush::operator $=$}\label{wxbrushassignment}
 291
 292 \func{wxBrush\&}{operator $=$}{\param{const wxBrush\& }{brush}}
 293
 294 Assignment operator, using \helpref{reference counting}{trefcount}.
 295
 296
 297 \membersection{wxBrush::operator $==$}\label{wxbrushequals}
 298
 299 \func{bool}{operator $==$}{\param{const wxBrush\& }{brush}}
 300
 301 Equality operator.
 302 See \helpref{reference-counted object comparison}{refcountequality} for more info.
 303
 304
 305 \membersection{wxBrush::operator $!=$}\label{wxbrushnotequals}
 306
 307 \func{bool}{operator $!=$}{\param{const wxBrush\& }{brush}}
 308
 309 Inequality operator.
 310 See \helpref{reference-counted object comparison}{refcountequality} for more info.
 311
 312
 313 \section{\class{wxBrushList}}\label{wxbrushlist}
 314
 315 A brush list is a list containing all brushes which have been created.
 316
 317 \wxheading{Derived from}
 318
 319 \helpref{wxList}{wxlist}\\
 320 \helpref{wxObject}{wxobject}
 321
 322 \wxheading{Include files}
 323
 324 <wx/gdicmn.h>
 325
 326 \wxheading{Remarks}
 327
 328 There is only one instance of this class: {\bf wxTheBrushList}.  Use
 329 this object to search for a previously created brush of the desired
 330 type and create it if not already found. In some windowing systems,
 331 the brush may be a scarce resource, so it can pay to reuse old
 332 resources if possible. When an application finishes, all brushes will
 333 be deleted and their resources freed, eliminating the possibility of
 334 `memory leaks'. However, it is best not to rely on this automatic
 335 cleanup because it can lead to double deletion in some circumstances.
 336
 337 There are two mechanisms in recent versions of wxWidgets which make the
 338 brush list less useful than it once was. Under Windows, scarce resources
 339 are cleaned up internally if they are not being used. Also, a reference
 340 counting mechanism applied to all GDI objects means that some sharing
 341 of underlying resources is possible. You don't have to keep track of pointers,
 342 working out when it is safe delete a brush, because the reference counting does
 343 it for you. For example, you can set a brush in a device context, and then
 344 immediately delete the brush you passed, because the brush is `copied'.
 345
 346 So you may find it easier to ignore the brush list, and instead create
 347 and copy brushes as you see fit. If your Windows resource meter suggests
 348 your application is using too many resources, you can resort to using
 349 GDI lists to share objects explicitly.
 350
 351 The only compelling use for the brush list is for wxWidgets to keep
 352 track of brushes in order to clean them up on exit. It is also kept for
 353 backward compatibility with earlier versions of wxWidgets.
 354
 355 \wxheading{See also}
 356
 357 \helpref{wxBrush}{wxbrush}
 358
 359 \latexignore{\rtfignore{\wxheading{Members}}}
 360
 361
 362 \membersection{wxBrushList::wxBrushList}\label{wxbrushlistconstr}
 363
 364 \func{void}{wxBrushList}{\void}
 365
 366 Constructor. The application should not construct its own brush list:
 367 use the object pointer {\bf wxTheBrushList}.
 368
 369
 370 \membersection{wxBrushList::FindOrCreateBrush}\label{wxbrushlistfindorcreatebrush}
 371
 372 \func{wxBrush *}{FindOrCreateBrush}{\param{const wxColour\& }{colour}, \param{int}{ style = wxSOLID}}
 373
 374 Finds a brush with the specified attributes and returns it, else creates a new brush, adds it
 375 to the brush list, and returns it.
 376
 377 \wxheading{Parameters}
 378
 379 \docparam{colour}{Colour object.}
 380
 381 \docparam{style}{Brush style. See \helpref{wxBrush::SetStyle}{wxbrushsetstyle} for a list of styles.}
 382
 383