Improved vertical alignment of text in FbTk::TextButton

The old formula for vertical align text inside FbTk::TextButton ('height/2 +
font_ascent/2 - 1') produced not always good looking results, escpecially
when different fonts are involved (eg, ClockTool and WorkspaceName have
different fonts and font-sizes).

'(height - font_ascent) / 2 - 1' produces better results.

Additional changes:

* added ASCII-Art to document the involved entities when calculating the
  baseline
* rewritten tests/testFont.cc to accept multiples texts and multiple
  fonts
* removed some internal parts of FbTk::Font from the public interface

1 files changed, 2 insertions, 2 deletions

diff --git a/src/FbTk/TextButton.hh b/src/FbTk/TextButton.hh
index a1c8b0e..eb0beca 100644
--- a/src/FbTk/TextButton.hh
+++ b/src/FbTk/TextButton.hh
@@ -56,7 +56,8 @@ public:
 
     void exposeEvent(XExposeEvent &event);
 
-    void renderForeground(FbDrawable &drawable);
+    //void renderForeground(FbDrawable &drawable);
+    void renderForeground(FbWindow &win, FbDrawable &drawable);
 
     FbTk::Justify justify() const { return m_justify; }
     const BiDiString &text() const { return m_text; }
@@ -65,7 +66,6 @@ public:
     unsigned int textWidth() const;
     int bevel() const { return m_bevel; }
 
-    void renderForeground(FbWindow &win, FbDrawable &drawable);
 
 protected:
     virtual void drawText(int x_offset, int y_offset, FbDrawable *drawable_override);