htrace-htraced/src/web/app/time_cursor.js

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 */

var htrace = htrace || {};

// Draws a vertical bar selecting a time.
htrace.TimeCursor = function(params) {
  this.selectedTime = -1;
  for (var k in params) {
    this[k]=params[k];
  }

  this.positionToTime = function(x) {
    if ((x < this.x0) || (x > this.xF)) {
      return -1;
    }
    return this.begin +
      (((x - this.x0) * (this.end - this.begin)) / (this.xF - this.x0));
  };

  this.timeToPosition = function(time) {
    return this.x0 + (((time - this.begin) *
        (this.xF - this.x0)) / (this.end - this.begin));
  };

  this.draw = function() {
    if (this.selectedTime != -1) {
      this.ctx.save();
      this.ctx.beginPath();
      this.ctx.rect(this.x0, this.y0,
          this.xF - this.x0, this.yF - this.y0);
      this.ctx.clip();
      this.ctx.strokeStyle="#ff0000";
      var x = this.timeToPosition(this.selectedTime);
      this.ctx.beginPath();
      this.ctx.moveTo(x, this.y0);
      this.ctx.lineTo(x, this.yF);
      this.ctx.stroke();
      this.ctx.restore();
    }
  };

  this.handleMouseMove = function(x, y) {
    if ((y >= this.y0) && (y <= this.yF) &&
        (x >= this.x0) && (x <= this.xF)) {
      this.selectedTime = this.positionToTime(x);
      if (this.selectedTime < 0) {
        $(this.el).val("");
      } else {
        $(this.el).val(htrace.dateToString(this.selectedTime));
      }
      return true;
    }
    return false;
  };

  return this;
};