Grid Layout Support.

This changeset adds basic support for grid layouts:

- Freeform mode where you can drag & drop anywhere in the layout, and
  guidelines are offered to align with other left boundaries, right
  boundaries, baseline vertical alignment and center layout horizontal
  alingment.  In addition, it also offers "preferred spacing"
  positioning, using the recommended distance between widgets.

  Also, during a drag a regular 16x16 grid is also (faintly) shown and
  (when there are no alignment matches as explained above) the
  position snaps to this grid.

  We also show the grid-structure (rows and columns, not the regular
  snapping grid) during drags to make it more obvious that behind the
  scenes there is a grid (because some other operations might shift
  rows and columns so it's important to present the right user model.)

  The freeform grid layout editor will automatically create rows and
  columns and size them using spacers which are hidden from the user,
  and on deletion these are automatically cleaned up as well.

- Grid mode where you can drag to any given cell, or between any two
  rows or columns.

- Some layout actions for manipulating the grid (add/remove row and
  column, adjust the gravity, toggle modes.)

This CL also contains various diagnostics code for the grid mode, and
does not yet correctly support dragging multiple views simultaneously.

Change-Id: Ie9ec54805039645e3db78d19095da86b04e44ca0

1 files changed, 11 insertions, 0 deletions

diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GCWrapper.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GCWrapper.java
index cd4105d91..b1366a374 100755
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GCWrapper.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/GCWrapper.java
@@ -488,6 +488,17 @@ public class GCWrapper implements IGraphics {
         return color;
     }
 
+    // dots
+
+    public void drawPoint(int x, int y) {
+        checkGC();
+        useStrokeAlpha();
+        x = mHScale.translate(x);
+        y = mVScale.translate(y);
+
+        getGc().drawPoint(x, y);
+    }
+
     // arrows
 
     private static final int MIN_LENGTH = 10;