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Diffstat (limited to 'doc/man/man3/tqpixmapcache.3qt')
| -rw-r--r-- | doc/man/man3/tqpixmapcache.3qt | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/doc/man/man3/tqpixmapcache.3qt b/doc/man/man3/tqpixmapcache.3qt index df41068cc..7054206ec 100644 --- a/doc/man/man3/tqpixmapcache.3qt +++ b/doc/man/man3/tqpixmapcache.3qt @@ -18,7 +18,7 @@ The TQPixmapCache class provides an application-global cache for pixmaps. .PP This class is a tool for optimized drawing with TQPixmap. You can use it to store temporary pixmaps that are expensive to generate without using more storage space than cacheLimit(). Use insert() to insert pixmaps, find() to find them and clear() to empty the cache. .PP -For example, QRadioButton has a non-trivial visual representation so we don't want to regenerate a pixmap whenever a radio button is displayed or changes state. In the function QRadioButton::drawButton(), we do not draw the radio button directly. Instead, we first check the global pixmap cache for a pixmap with the key "$qt_radio_nnn_", where \fCnnn\fR is a numerical value that specifies the the radio button state. If a pixmap is found, we bitBlt() it onto the widget and return. Otherwise, we create a new pixmap, draw the radio button in the pixmap, and finally insert the pixmap in the global pixmap cache, using the key above. The bitBlt() is ten times faster than drawing the radio button. All radio buttons in the program share the cached pixmap since TQPixmapCache is application-global. +For example, TQRadioButton has a non-trivial visual representation so we don't want to regenerate a pixmap whenever a radio button is displayed or changes state. In the function TQRadioButton::drawButton(), we do not draw the radio button directly. Instead, we first check the global pixmap cache for a pixmap with the key "$qt_radio_nnn_", where \fCnnn\fR is a numerical value that specifies the the radio button state. If a pixmap is found, we bitBlt() it onto the widget and return. Otherwise, we create a new pixmap, draw the radio button in the pixmap, and finally insert the pixmap in the global pixmap cache, using the key above. The bitBlt() is ten times faster than drawing the radio button. All radio buttons in the program share the cached pixmap since TQPixmapCache is application-global. .PP TQPixmapCache contains no member data, only static functions to access the global pixmap cache. It creates an internal TQCache for caching the pixmaps. .PP |