1 files changed, 97 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/ui/ScrollBarView.java b/src/com/android/gallery3d/ui/ScrollBarView.java
new file mode 100644
index 000000000..34fbcef7a
--- /dev/null
+++ b/src/com/android/gallery3d/ui/ScrollBarView.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.gallery3d.ui;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.util.TypedValue;
+
+import com.android.gallery3d.glrenderer.GLCanvas;
+import com.android.gallery3d.glrenderer.NinePatchTexture;
+
+public class ScrollBarView extends GLView {
+    @SuppressWarnings("unused")
+    private static final String TAG = "ScrollBarView";
+
+    private int mBarHeight;
+
+    private int mGripHeight;
+    private int mGripPosition;  // left side of the grip
+    private int mGripWidth;     // zero if the grip is disabled
+    private int mGivenGripWidth;
+
+    private int mContentPosition;
+    private int mContentTotal;
+
+    private NinePatchTexture mScrollBarTexture;
+
+    public ScrollBarView(Context context, int gripHeight, int gripWidth) {
+        TypedValue outValue = new TypedValue();
+        context.getTheme().resolveAttribute(
+                android.R.attr.scrollbarThumbHorizontal, outValue, true);
+        mScrollBarTexture = new NinePatchTexture(
+                context, outValue.resourceId);
+        mGripPosition = 0;
+        mGripWidth = 0;
+        mGivenGripWidth = gripWidth;
+        mGripHeight = gripHeight;
+    }
+
+    @Override
+    protected void onLayout(
+            boolean changed, int left, int top, int right, int bottom) {
+        if (!changed) return;
+        mBarHeight = bottom - top;
+    }
+
+    // The content position is between 0 to "total". The current position is
+    // in "position".
+    public void setContentPosition(int position, int total) {
+        if (position == mContentPosition && total == mContentTotal) {
+            return;
+        }
+
+        invalidate();
+
+        mContentPosition = position;
+        mContentTotal = total;
+
+        // If the grip cannot move, don't draw it.
+        if (mContentTotal <= 0) {
+            mGripPosition = 0;
+            mGripWidth = 0;
+            return;
+        }
+
+        // Map from the content range to scroll bar range.
+        //
+        // mContentTotal --> getWidth() - mGripWidth
+        // mContentPosition --> mGripPosition
+        mGripWidth = mGivenGripWidth;
+        float r = (getWidth() - mGripWidth) / (float) mContentTotal;
+        mGripPosition = Math.round(r * mContentPosition);
+    }
+
+    @Override
+    protected void render(GLCanvas canvas) {
+        super.render(canvas);
+        if (mGripWidth == 0) return;
+        Rect b = bounds();
+        int y = (mBarHeight - mGripHeight) / 2;
+        mScrollBarTexture.draw(canvas, mGripPosition, y, mGripWidth, mGripHeight);
+    }
+}