code: private void fixTrans() {
          matrix.getValues(m);
          float transX = m[Matrix.MTRANS_X];
          float transY = m[Matrix.MTRANS_Y];
  
          float fixTransX = getFixTrans(transX, viewWidth, getImageWidth());
          float fixTransY = getFixTrans(transY, viewHeight, getImageHeight());
  
          if (fixTransX != 0 || fixTransY != 0) {
              matrix.postTranslate(fixTransX, fixTransY);
          }
      }
docs: Performs boundary checking and fixes the image matrix if it
  is out of bounds.