/**
 * @provide pskl.drawingtools.Move
 *
 * @require pskl.utils
 */
(function() {
  var ns = $.namespace("pskl.drawingtools");

  ns.Move = function() {
    this.toolId = ns.Move.TOOL_ID;
    this.helpText = "Move tool";

    // Stroke's first point coordinates (set in applyToolAt)
    this.startCol = null;
    this.startRow = null;
  };

  ns.Move.TOOL_ID = "tool-move";

  pskl.utils.inherit(ns.Move, ns.BaseTool);

  /**
   * @override
   */
  ns.Move.prototype.applyToolAt = function(col, row, color, frame, overlay, event) {
    this.startCol = col;
    this.startRow = row;
    this.frameClone = frame.clone();
  };

  ns.Move.prototype.moveToolAt = function(col, row, color, frame, overlay, event) {
    var colDiff = col - this.startCol, rowDiff = row - this.startRow;
    this.shiftFrame(colDiff, rowDiff, frame, this.frameClone);
  };

  ns.Move.prototype.shiftFrame = function (colDiff, rowDiff, frame, reference) {
    var color;
    for (var col = 0 ; col < frame.getWidth() ; col++) {
      for (var row = 0 ; row < frame.getHeight() ; row++) {
        if (reference.containsPixel(col - colDiff, row - rowDiff)) {
          color = reference.getPixel(col - colDiff, row - rowDiff);
        } else {
          color = Constants.TRANSPARENT_COLOR;
        }
        frame.setPixel(col, row, color);
      }
    }
  };

  /**
   * @override
   */
  ns.Move.prototype.releaseToolAt = function(col, row, color, frame, overlay, event) {
    this.moveToolAt(col, row, color, frame, overlay);
  };
})();