Fixed|libappfw: DocumentWidget content overflowing the right edge

Fixes a layout issue with DocumentWidget where it was possible that
tabbed lines would extend beyond the predetermined bounds for the
text content. This was occurring for instance in the About -> GL popup
when the first set of tabbed lines were shorter than the second set.

Todo for later: Improve FontLineWrapping to precalculate tab stop
alignment so this can be known before vertex generation.

doomsday/libappfw/include/de/framework/gltextcomposer.h

@@ -108,6 +108,21 @@ class LIBAPPFW_PUBLIC GLTextComposer : public Asset
                       ui::Alignment const &lineAlign,
                       Vector4f const &color = Vector4f(1, 1, 1, 1));
 
+    /**
+     * Returns the maximum width of the generated vertices. This is only valid after
+     * makeVertices() has been called.
+     *
+     * This may be larger than the maximum width as determined by FontLineWrapping if
+     * tabbed lines are used in the text. This is because text segments are aligned
+     * with tab stops only during makeVertices().
+     *
+     * @todo Ideally tap stop alignment should be done in FontLineWrapping, so that the
+     * maximum width would be known prior to generating the vertices.
+     *
+     * @return Maximum width of the generated vertices.
+     */
+    int verticesMaxWidth() const;
+
 private:
     DENG2_PRIVATE(d)
 };

doomsday/libappfw/src/fontlinewrapping.cpp

@@ -575,7 +575,7 @@ void FontLineWrapping::wrapTextToWidth(String const &text, Font::RichFormat cons
             pos = wholeLine.end + 1;
         }
 
-        // Process the content is distinct ranges divided by untabbed content.
+        // Process the content in distinct ranges divided by untabbed content.
         Rangei tabRange = d->findNextTabbedRange(0);
         forever
         {

doomsday/libappfw/src/gltextcomposer.cpp

@@ -28,13 +28,14 @@ static Rangei const MAX_VISIBLE_RANGE(0, 0x7fffffff);
 
 DENG2_PIMPL(GLTextComposer)
 {    
-    Font const *font;
-    Atlas *atlas;
+    Font const *font = nullptr;
+    Atlas *atlas = nullptr;
     String text;
-    FontLineWrapping const *wraps;
+    FontLineWrapping const *wraps = nullptr;
     Font::RichFormat format;
-    bool needRedo;
-    Rangei visibleLineRange; ///< Only these lines will be updated/drawn.
+    bool needRedo = false;
+    Rangei visibleLineRange { MAX_VISIBLE_RANGE }; ///< Only these lines will be updated/drawn.
+    int maxGeneratedWidth = 0;
 
     struct Line {
         struct Segment {
@@ -53,10 +54,7 @@ DENG2_PIMPL(GLTextComposer)
     typedef QList<Line> Lines;
     Lines lines;
 
-    Instance(Public *i)
-        : Base(i), font(0), atlas(0), wraps(0), needRedo(false),
-          visibleLineRange(MAX_VISIBLE_RANGE)
-    {}
+    Instance(Public *i) : Base(i) {}
 
     ~Instance()
     {
@@ -489,6 +487,8 @@ void GLTextComposer::makeVertices(Vertices &triStrip,
         }
     }
 
+    d->maxGeneratedWidth = 0;
+
     // Generate vertices for each line.
     for(int i = 0; i < d->wraps->height(); ++i)
     {
@@ -528,13 +528,21 @@ void GLTextComposer::makeVertices(Vertices &triStrip,
 
                 Rectanglef const uv = d->atlas->imageRectf(seg.id);
 
-                triStrip.makeQuad(Rectanglef::fromSize(linePos + Vector2f(seg.x, 0), size),
-                                  color, uv);
+                auto const segRect = Rectanglef::fromSize(linePos + Vector2f(seg.x, 0), size);
+                triStrip.makeQuad(segRect, color, uv);
+
+                // Keep track of how wide the geometry really is.
+                d->maxGeneratedWidth = de::max(d->maxGeneratedWidth, int(segRect.right() - p.x));
             }
         }
 
         p.y += d->font->lineSpacing().value();
     }
 }
 
+int GLTextComposer::verticesMaxWidth() const
+{
+    return d->maxGeneratedWidth;
+}
+
 } // namespace de

doomsday/libappfw/src/widgets/documentwidget.cpp

@@ -223,6 +223,9 @@ public Font::RichFormat::IStyle
                 VertexBuf::Builder verts;
                 glText.makeVertices(verts, Vector2i(0, 0), ui::AlignLeft);
                 drawable.buffer<VertexBuf>(ID_TEXT).setVertices(gl::TriangleStrip, verts, gl::Static);
+
+                // Update content size to match the generated vertices exactly.
+                self.setContentWidth(glText.verticesMaxWidth());
             }
 
             uScrollMvpMatrix = root().projMatrix2D() *