Set layout editor scrollbar increments

Fix 13097: Gingerbread Layout Editor scroll bar bugs, part 1:
Set the layout editor scrollbar increments to 20 (they were 1, meaning
that each click on the scrollbar down button would scroll the view by
one pixel rather than a "chunk" like 20).

Set the scrollbar page increment to the visual height of the
canvas. This means that if you click below the visible range in the
scrollbar it will jump a full scrollbar increment, as expected.

(This is the first half of 13097. The second half deals with something
unrelated.)

Change-Id: I80c544b749d08d1fdc127d682ef8a75aed9aa8e7

2 files changed, 5 insertions, 0 deletions

diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/CanvasTransform.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/CanvasTransform.java
index 8a4ebc6..f905f35 100644
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/CanvasTransform.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/CanvasTransform.java
@@ -58,6 +58,7 @@ public class CanvasTransform implements ICanvasTransform {
                 CanvasTransform.this.mCanvas.redraw();
             }
         });
+        mScrollbar.setIncrement(20);
     }
 
     /**
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/LayoutCanvas.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/LayoutCanvas.java
index 443171e..389b25f 100755
--- a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/LayoutCanvas.java
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/LayoutCanvas.java
@@ -255,6 +255,10 @@ class LayoutCanvas extends Canvas {
                 super.controlResized(e);
                 mHScale.setClientSize(getClientArea().width);
                 mVScale.setClientSize(getClientArea().height);
+
+                Rectangle canvasBounds = LayoutCanvas.this.getBounds();
+                getHorizontalBar().setPageIncrement(canvasBounds.width);
+                getVerticalBar().setPageIncrement(canvasBounds.height);
             }
         });