@Override
 public void onClick(View v) {
   if (v.equals(mColorPickerBtn)) {
     // Toggle
     boolean bIsColorPickerMode = !mSCanvas.isColorPickerMode();
     mSCanvas.setColorPickerMode(bIsColorPickerMode);
     mColorPickerBtn.setSelected(bIsColorPickerMode);
   }
 }
  // Update tool button
  private void updateModeState() {
    int nCurMode = mSCanvas.getCanvasMode();
    mPenBtn.setSelected(nCurMode == SCanvasConstants.SCANVAS_MODE_INPUT_PEN);
    mEraserBtn.setSelected(nCurMode == SCanvasConstants.SCANVAS_MODE_INPUT_ERASER);
    mTextBtn.setSelected(nCurMode == SCanvasConstants.SCANVAS_MODE_INPUT_TEXT);
    mFillingBtn.setSelected(nCurMode == SCanvasConstants.SCANVAS_MODE_INPUT_FILLING);

    // Reset color picker tool when Eraser Mode
    if (nCurMode == SCanvasConstants.SCANVAS_MODE_INPUT_ERASER) mSCanvas.setColorPickerMode(false);
    mColorPickerBtn.setEnabled(nCurMode != SCanvasConstants.SCANVAS_MODE_INPUT_ERASER);
    mColorPickerBtn.setSelected(mSCanvas.isColorPickerMode());
  }