* QLPainter::text():

- reorganize the code to minimize indentation by returning early for special cases
- use a pixmap cache for word drawing. This can be disabled by setting USE_PIXMAP_CACHE to 0 at the top of QLPainter.cpp.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@19513 a592a061-630c-0410-9148-cb99ea01b6c8

diff --git a/src/frontends/qt4/QLPainter.cpp b/src/frontends/qt4/QLPainter.cpp
index 4ed39cbdae7e248da457bceb8741b8c017916ba6..2c6d9e7c620654bd4605a47259a10403151df4ed 100644 (file)
--- a/src/frontends/qt4/QLPainter.cpp
+++ b/src/frontends/qt4/QLPainter.cpp
@@ -11,8 +11,6 @@
 
 #include <config.h>
 
-#include <QTextLayout>
-
 #include "QLPainter.h"
 
 #include "GuiApplication.h"
@@ -28,12 +26,36 @@
 
 #include "support/unicode.h"
 
+#include <QPixmapCache>
+#include <QTextLayout>
+
+// Set this to one for enabling the use of a Pixmap cache when drawing
+// text. This is especially useful for older PPC/Mac systems.
+#define USE_PIXMAP_CACHE 1
+
 using std::endl;
 using std::string;
 
 namespace lyx {
 namespace frontend {
 
+namespace {
+
+bool const usePixmapCache = USE_PIXMAP_CACHE;
+
+QString generateStringSignature(QString const & str, Font const & f)
+{
+       QString sig = str;
+       sig.append(QChar(static_cast<short>(f.family())));
+       sig.append(QChar(static_cast<short>(f.series())));
+       sig.append(QChar(static_cast<short>(f.realShape())));
+       sig.append(QChar(static_cast<short>(f.size())));
+       sig.append(QChar(static_cast<short>(f.color())));
+       return sig;
+}
+
+} // anon namespace
+
 QLPainter::QLPainter(QPaintDevice * device)
        : QPainter(device), Painter()
 {
@@ -243,42 +265,89 @@ int QLPainter::text(int x, int y, docstring const & s,
 
        int textwidth;
 
-       if (f.realShape() != Font::SMALLCAPS_SHAPE) {
+       if (f.realShape() == Font::SMALLCAPS_SHAPE) {
+               textwidth = smallCapsText(x, y, str, f);
+               if (f.underbar() == Font::ON)
+                       underline(f, x, y, textwidth);
+               return textwidth;
+       }
+
+       // Here we use the font width cache instead of
+       //   textwidth = fontMetrics().width(str);
+       // because the above is awfully expensive on MacOSX
+       textwidth = fi.metrics->width(s);
+       if (f.underbar() == Font::ON)
+               underline(f, x, y, textwidth);
+
+       if (!isDrawingEnabled())
+               return textwidth;
+
+       // Qt4 does not display a glyph whose codepoint is the
+       // same as that of a soft-hyphen (0x00ad), unless it
+       // occurs at a line-break. As a kludge, we force Qt to
+       // render this glyph using a one-column line.
+       if (s.size() == 1 && str[0].unicode() == 0x00ad) {
+               QTextLayout adsymbol(str);
+               adsymbol.setFont(fi.font);
+               adsymbol.beginLayout();
+               QTextLine line = adsymbol.createLine();
+               line.setNumColumns(1);
+               line.setPosition(QPointF(0, -line.ascent()));
+               adsymbol.endLayout();
+               line.draw(this, QPointF(x, y));
+               return textwidth;
+       }
+
+       if (!usePixmapCache) {
+               // don't use the pixmap cache,
+               // draw directly onto the painting device
                setQPainterPen(f.realColor());
                if (font() != fi.font)
                        setFont(fi.font);
                // We need to draw the text as LTR as we use our own bidi code.
                setLayoutDirection(Qt::LeftToRight);
-               if (isDrawingEnabled()) {
-                       LYXERR(Debug::PAINTING) << "draw " << std::string(str.toUtf8())
-                               << " at " << x << "," << y << std::endl;
-                       // Qt4 does not display a glyph whose codepoint is the
-                       // same as that of a soft-hyphen (0x00ad), unless it
-                       // occurs at a line-break. As a kludge, we force Qt to
-                       // render this glyph using a one-column line.
-                       if (s.size() == 1 && str[0].unicode() == 0x00ad) {
-                               QTextLayout adsymbol(str);
-                               adsymbol.setFont(fi.font);
-                               adsymbol.beginLayout();
-                               QTextLine line = adsymbol.createLine();
-                               line.setNumColumns(1);
-                               line.setPosition(QPointF(0, -line.ascent()));
-                               adsymbol.endLayout();
-                               line.draw(this, QPointF(x, y));
-                       } else
-                               drawText(x, y, str);
-               }
-               // Here we use the font width cache instead of
-               //   textwidth = fontMetrics().width(str);
-               // because the above is awfully expensive on MacOSX
-               textwidth = fi.metrics->width(str);
-       } else {
-               textwidth = smallCapsText(x, y, str, f);
+               // We need to draw the text as LTR as we use our own bidi code.
+               setLayoutDirection(Qt::LeftToRight);
+               drawText(x, y, str);
+               LYXERR(Debug::PAINTING) << "draw " << std::string(str.toUtf8())
+                       << " at " << x << "," << y << std::endl;
+               return textwidth;
        }
 
-       if (f.underbar() == Font::ON) {
-               underline(f, x, y, textwidth);
+       QPixmap pm;
+       QString key = generateStringSignature(str, f);
+       // Warning: Left bearing is in general negative! Only the case
+       // where left bearing is negative is of interest WRT the the 
+       // pixmap width and the text x-position.
+       // Only the left bearing of the first character is important
+       // as we always write from left to right, even for
+       // right-to-left languages.
+       int const lb = std::min(fi.metrics->lbearing(s[0]), 0);
+       int const mA = fi.metrics->maxAscent();
+       if (!QPixmapCache::find(key, pm)) {
+               // Only the right bearing of the last character is
+               // important as we always write from left to right,
+               // even for right-to-left languages.
+               int const rb = fi.metrics->rbearing(s[s.size()-1]);
+               int const w = textwidth + rb - lb;
+               int const mD = fi.metrics->maxDescent();
+               int const h = mA + mD;
+               pm = QPixmap(w, h);
+               pm.fill(Qt::transparent);
+               QLPainter p(&pm);
+               p.setQPainterPen(f.realColor());
+               if (p.font() != fi.font)
+                       p.setFont(fi.font);
+               // We need to draw the text as LTR as we use our own bidi code.
+               p.setLayoutDirection(Qt::LeftToRight);
+               p.drawText(-lb, mA, str);
+               QPixmapCache::insert(key, pm);
+               LYXERR(Debug::PAINTING) << "h=" << h << "  mA=" << mA << "  mD=" << mD
+                       << "  w=" << w << "  lb=" << lb << "  tw=" << textwidth 
+                       << "  rb=" << rb << endl;
        }
+       // Draw the cached pixmap.
+       drawPixmap(x + lb, y - mA, pm);
 
        return textwidth;
 }