Add prepare() function to QStaticText

Allow the QStaticText layout to be completely defined prior to painting
by introducing a function for setting the font and transform on the
object ahead of using it with a QPainter.

2 files changed, 29 insertions, 1 deletions

diff --git a/src/gui/text/qstatictext.cpp b/src/gui/text/qstatictext.cpp
index 56950ed..9a0ddca 100644
--- a/src/gui/text/qstatictext.cpp
+++ b/src/gui/text/qstatictext.cpp
@@ -152,6 +152,29 @@ void QStaticText::detach()
 }
 
 /*!
+  Prepares the QStaticText object for being painted with the given \a matrix and the given
+  \a font to avoid overhead when the actual drawStaticText() call is made.
+
+  When drawStaticText() is called, the layout of the QStaticText will be recalculated if the
+  painter's font or matrix is different from the one used for the currently cached layout. By
+  default, QStaticText will use a default constructed QFont and an identity matrix to create
+  its layout.
+
+  To avoid the overhead of creating the layout the first time you draw the QStaticText with
+  a painter whose matrix or font are different from the defaults, you can use the prepare()
+  function and pass in the matrix and font you expect to use when drawing the text.
+
+  \sa QPainter::setFont(), QPainter::setMatrix()
+*/
+void QStaticText::prepare(const QTransform &matrix, const QFont &font)
+{
+    d_ptr->matrix = matrix;
+    d_ptr->font = font;
+    d_ptr->init();
+}
+
+
+/*!
     Assigns \a other to this QStaticText.
 */
 QStaticText &QStaticText::operator=(const QStaticText &other)
diff --git a/src/gui/text/qstatictext.h b/src/gui/text/qstatictext.h
index c7b5429..e507d82 100644
--- a/src/gui/text/qstatictext.h
+++ b/src/gui/text/qstatictext.h
@@ -42,9 +42,12 @@
 #ifndef QSTATICTEXT_H
 #define QSTATICTEXT_H
 
+#include <QtCore/qsize.h>
 #include <QtCore/qstring.h>
+
+#include <QtGui/qtransform.h>
 #include <QtGui/qfont.h>
-#include <QtCore/qsize.h>
+
 
 QT_BEGIN_HEADER
 
@@ -67,6 +70,8 @@ public:
     void setMaximumSize(const QSizeF &maximumSize);
     QSizeF maximumSize() const;
 
+    void prepare(const QTransform &matrix, const QFont &font);
+
     QStaticText &operator=(const QStaticText &);
     bool operator==(const QStaticText &) const;
     bool operator!=(const QStaticText &) const;