Client: Added FontLineWrapping, utility for wrapping text

doomsday/client/include/ui/widgets/fontlinewrapping.h

@@ -0,0 +1,56 @@
+/** @file fontlinewrapping.h  Font line wrapping.
+ *
+ * @authors Copyright (c) 2013 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * @par License
+ * GPL: http://www.gnu.org/licenses/gpl.html
+ *
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details. You should have received a copy of the GNU
+ * General Public License along with this program; if not, see:
+ * http://www.gnu.org/licenses</small> 
+ */
+
+#ifndef DENG_CLIENT_FONTLINEWRAPPING_H
+#define DENG_CLIENT_FONTLINEWRAPPING_H
+
+#include <de/String>
+#include <de/Font>
+#include <de/shell/ILineWrapping>
+
+/**
+ * Line wrapper that uses a particular font and calculates widths in pixels.
+ * Height is still in lines, though. The wrapper cannot be used before the
+ * font has been defined.
+ */
+class FontLineWrapping : public de::shell::ILineWrapping
+{
+public:
+    FontLineWrapping();
+
+    void setFont(de::Font const &font);
+    de::Font const &font() const;
+
+    bool isEmpty() const;
+    void clear();
+    void wrapTextToWidth(de::String const &text, int maxWidth);
+    de::shell::WrappedLine line(int index) const;
+    int width() const;
+    int height() const;
+
+    /**
+     * Calculates the total height of the wrapped lined in pixels, taking into
+     * consideration the appropriate amount of line spacing.
+     */
+    int totalHeightInPixels() const;
+
+private:
+    DENG2_PRIVATE(d)
+};
+
+#endif // DENG_CLIENT_FONTLINEWRAPPING_H

doomsday/client/src/ui/widgets/fontlinewrapping.cpp

@@ -0,0 +1,171 @@
+/** @file fontlinewrapping.cpp  Font line wrapping.
+ *
+ * @authors Copyright (c) 2013 Jaakko Keränen <jaakko.keranen@iki.fi>
+ *
+ * @par License
+ * GPL: http://www.gnu.org/licenses/gpl.html
+ *
+ * <small>This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version. This program is distributed in the hope that it
+ * will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
+ * Public License for more details. You should have received a copy of the GNU
+ * General Public License along with this program; if not, see:
+ * http://www.gnu.org/licenses</small> 
+ */
+
+#include "ui/widgets/fontlinewrapping.h"
+
+using namespace de;
+using namespace de::shell;
+
+DENG2_PIMPL_NOREF(FontLineWrapping)
+{
+    Font const *font;
+    QList<WrappedLine> lines;
+    String text;
+
+    Instance() : font(0) {}
+
+    int rangeWidth(Range const &range) const
+    {
+        if(font)
+        {
+            return font->measure(text.substr(range.start, range.size())).width();
+        }
+        return 0;
+    }
+};
+
+FontLineWrapping::FontLineWrapping() : d(new Instance)
+{}
+
+void FontLineWrapping::setFont(Font const &font)
+{
+    d->font = &font;
+}
+
+Font const &FontLineWrapping::font() const
+{
+    DENG2_ASSERT(d->font != 0);
+    return *d->font;
+}
+
+bool FontLineWrapping::isEmpty() const
+{
+    return d->lines.isEmpty();
+}
+
+void FontLineWrapping::clear()
+{
+    d->lines.clear();
+    d->text.clear();
+}
+
+void FontLineWrapping::wrapTextToWidth(String const &text, int maxWidth)
+{
+    /**
+     * @note This is quite similar to MonospaceLineWrapping::wrapTextToWidth().
+     * Perhaps a generic method could be abstracted from these two.
+     */
+
+    QChar const newline('\n');
+
+    clear();
+
+    if(maxWidth < 1 || !d->font) return;
+
+    // This is the text that we will be wrapping.
+    d->text = text;
+
+    int begin = 0;
+    forever
+    {
+        // Newlines always cause a wrap.
+        int end = begin;
+        while(d->rangeWidth(Range(begin, end)) < maxWidth &&
+              end < text.size() && text.at(end) != newline) ++end;
+
+        if(end == text.size())
+        {
+            // Out of characters; time to stop.
+            d->lines.append(WrappedLine(Range(begin, text.size())));
+            break;
+        }
+
+        int const wrapPosMax = de::max(end - 1, begin + 1);
+
+        // Find a good (whitespace) break point.
+        while(!text.at(end).isSpace())
+        {
+            if(--end == begin)
+            {
+                // Ran out of non-space chars, force a break.
+                end = wrapPosMax;
+                break;
+            }
+        }
+
+        if(text.at(end) == newline)
+        {
+            // The newline will be omitted from the wrapped lines.
+            d->lines.append(WrappedLine(Range(begin, end)));
+            begin = end + 1;
+        }
+        else
+        {
+            if(text.at(end).isSpace()) ++end;
+            d->lines.append(WrappedLine(Range(begin, end)));
+            begin = end;
+        }
+    }
+
+    // Mark the final line.
+    d->lines.last().isFinal = true;
+}
+
+WrappedLine FontLineWrapping::line(int index) const
+{
+    DENG2_ASSERT(index >= 0 && index < height());
+    return d->lines[index];
+}
+
+int FontLineWrapping::width() const
+{
+    if(!d->font) return 0;
+
+    int w = 0;
+    for(int i = 0; i < d->lines.size(); ++i)
+    {
+        WrappedLine const &span = d->lines[i];
+        w = de::max(w, d->rangeWidth(span.range));
+    }
+    return w;
+}
+
+int FontLineWrapping::height() const
+{
+    return d->lines.size();
+}
+
+int FontLineWrapping::totalHeightInPixels() const
+{
+    if(!d->font) return 0;
+
+    int const lines = height();
+    int pixels = 0;
+
+    if(lines > 1)
+    {
+        // Full baseline-to-baseline spacing.
+        pixels += (lines - 1) * d->font->lineSpacing().value();
+    }
+    if(lines > 0)
+    {
+        // The last (or a single) line is just one 'font height' tall.
+        pixels += d->font->height().value();
+    }
+    return pixels;
+}