Move labels into KnobView

The main reason for these to be inside the KnobView is so that they can
be part of the touch target for the knob. A more general approach would
be to make the Knob a container that can contain TextView widgets, but
this is simpler.

android/res/layout/piano2.xml

@@ -8,29 +8,6 @@
     android:layout_height="fill_parent"
     android:stretchColumns="*"
     android:shrinkColumns="*">
-  <TableRow>
-    <TextView
-        android:text="@string/cutoff"
-        android:id="@+id/cutoffLabel"
-        android:gravity="center_horizontal" />
-    <TextView
-        android:text="@string/resonance"
-        android:id="@+id/resonanceLabel"
-        android:gravity="center_horizontal" />
-    <TextView
-        android:text="@string/overdrive"
-        android:id="@+id/overdriveLabel"
-        android:gravity="center_horizontal" />
-    <TextView
-        android:text=""
-        android:gravity="center_horizontal" />
-    <TextView
-        android:text=""
-        android:gravity="center_horizontal" />
-    <TextView
-        android:text=""
-        android:gravity="center_horizontal" />
-  </TableRow>
   <TableRow>
     <com.levien.synthesizer.android.widgets.knob.KnobView
         android:id="@+id/cutoffKnob"
@@ -39,7 +16,8 @@
         app:max="1"
         android:layout_width="@dimen/knobsize"
         android:layout_height="@dimen/knobsize"
-        android:layout_margin="2dp" />
+        android:layout_margin="2dp"
+        app:label="@+string/cutoff" />
     <com.levien.synthesizer.android.widgets.knob.KnobView
         android:id="@+id/resonanceKnob"
         app:value="0.0"
@@ -47,7 +25,8 @@
         app:max="1"
         android:layout_width="@dimen/knobsize"
         android:layout_height="@dimen/knobsize"
-        android:layout_margin="2dp" />
+        android:layout_margin="2dp" 
+        app:label="@+string/resonance"/>
     <com.levien.synthesizer.android.widgets.knob.KnobView
         android:id="@+id/overdriveKnob"
         app:value="0.0"
@@ -55,7 +34,8 @@
         app:max="1"
         android:layout_width="@dimen/knobsize"
         android:layout_height="@dimen/knobsize"
-        android:layout_margin="2dp" />
+        android:layout_margin="2dp" 
+        app:label="@+string/overdrive"/>
     <LinearLayout
         android:orientation="vertical"
         android:layout_span="3" >

android/res/values/attrs.xml

@@ -7,6 +7,7 @@
     <attr name="value" format="float" />
     <attr name="min" format="float" />
     <attr name="max" format="float" />
+    <attr name="label" format="string" />
   </declare-styleable>
   <declare-styleable name="PianoView">
     <attr name="octaves" format="integer" />

android/src/com/levien/synthesizer/android/widgets/knob/KnobView.java

@@ -49,6 +49,7 @@ public class KnobView extends View {
     knobValue_ = a.getFloat(R.styleable.KnobView_value, 0.5f);
     min_ = a.getFloat(R.styleable.KnobView_min, 0.0f);
     max_ = a.getFloat(R.styleable.KnobView_max, 1.0f);
+    label_ = a.getString(R.styleable.KnobView_label);
     a.recycle();
 
     // Set up the drawing structures.
@@ -61,7 +62,7 @@ public class KnobView extends View {
     rect_ = new Rect();
     rectF_ = new RectF();
     innerRectF_ = new RectF();
-    textHeight_ = 18f * density;  // probably should be set by XML parameter
+    textHeight_ = 16f * density;  // probably should be set by XML parameter
     paint_.setTextSize(textHeight_);
 
     // The listener has to be set later.
@@ -163,6 +164,12 @@ public class KnobView extends View {
 
     getDrawingRect(rect_);
     rectF_.set(rect_);
+    // Apply padding.
+    rectF_.left += getPaddingLeft();
+    rectF_.right -= getPaddingRight();
+    rectF_.top += getPaddingTop();
+    rectF_.bottom -= getPaddingBottom();
+
     // Make it square.
     if (rectF_.height() > rectF_.width()) {
       float center = rectF_.centerY();
@@ -206,7 +213,7 @@ public class KnobView extends View {
     paint_.setStrokeWidth(strokeWidth_);
     canvas.drawCircle(rect_.exactCenterX(),
                       rect_.exactCenterY(),
-                      Math.min(rect_.width(), rect_.height()) * 0.45f - border,
+                      rectF_.width() * 0.45f - border,
                       paint_);
 
     // Draw text.
@@ -219,8 +226,13 @@ public class KnobView extends View {
     paint_.setStyle(Style.FILL);
     canvas.drawText(knobValueString,
                     rect_.centerX(),
-                    rect_.top + 0.8f * textHeight_,
+                    rectF_.top + 0.8f * textHeight_,
                     paint_);
+
+    if (label_ != null) {
+      paint_.setTypeface(Typeface.DEFAULT);
+      canvas.drawText(label_, rect_.centerX(), rectF_.bottom - 0.2f * textHeight_, paint_);
+    }
   }
 
   /**
@@ -317,6 +329,7 @@ public class KnobView extends View {
   private final float startAngle_ = 36f;  // relative to bottom
   private final float strokeWidth_;
   private float sensitivity_;
+  private String label_ = "labelg";
 
   // State of drag gesture
   private float xyAtTouch_;