skin_engine: Automatically create touch regions for skin bars

skin bars now automatically create the touch region the same size
as the bar on touchscreen targets. This means touches will
magically "just work" for reveresed bars (rtl or otherwise).

~5% padding is added on all 4 sides of the region rectangle but
this may need to be tweaked.

Please consider the 'progressbar' and 'volume' touchregion actions
to be deprecated.

Kudos to my new wife for figuring out the bleedingly obvious way to
do this!

Change-Id: I997a7bcaa70fce9885808aae27953c7676e9c2ff

1 files changed, 9 insertions, 0 deletions

diff --git a/manual/appendix/wps_tags.tex b/manual/appendix/wps_tags.tex
index 2d22b73..14e0308 100644
--- a/manual/appendix/wps_tags.tex
+++ b/manual/appendix/wps_tags.tex
@@ -676,6 +676,12 @@ display cycling round the defined sublines. See
   Some tags can be used to display a bar which draws according to the value of
   the tag. To use these tags like a bar you need to use the following parameters
   (\%XX should be replaced with the actual tag).
+  
+\opt{touchscreen}{
+    Volume and progress bars automatically create touch regions the same size
+    as the bar (slightly larger actually). This can be disabled with the
+    \config{notouch} option.
+}
 
 \begin{tagmap}
   \config{\%XX(x, y, width, height, [options])}
@@ -706,6 +712,9 @@ display cycling round the defined sublines. See
      ``slider'' option).
   \item[nobar] -- don't draw the bar or its frame (for use with the
     ``slider'' option).
+    \opt{touchscreen}{
+        \item[notouch] -- don't create the touchregion for progress/volume bars.
+    }
 \end{description}
 
 Example: \config{\%pb(0,0,-,-,-,nofill, slider, slider\_image, invert)} -- draw