src/third_party/trace-viewer/src/tracing/timeline_display_transform.js

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 'use strict';
   6
   7 base.require('base.utils');
   8
   9 base.exportTo('tracing', function() {
  10   function TimelineDisplayTransform(opt_that) {
  11     if (opt_that) {
  12       this.set(opt_that);
  13       return;
  14     }
  15     this.scaleX = 1;
  16     this.panX = 0;
  17     this.panY = 0;
  18   }
  19
  20   TimelineDisplayTransform.prototype = {
  21     set: function(that) {
  22       this.scaleX = that.scaleX;
  23       this.panX = that.panX;
  24       this.panY = that.panY;
  25     },
  26
  27     clone: function() {
  28       return new TimelineDisplayTransform(this);
  29     },
  30
  31     equals: function(that) {
  32       var eq = true;
  33       if (that === undefined || that === null)
  34         return false;
  35       eq &= this.panX === that.panX;
  36       eq &= this.panY === that.panY;
  37       eq &= this.scaleX === that.scaleX;
  38       return !!eq;
  39     },
  40
  41     almostEquals: function(that) {
  42       var eq = true;
  43       if (that === undefined || that === null)
  44         return false;
  45       eq &= Math.abs(this.panX - that.panX) < 0.001;
  46       eq &= Math.abs(this.panY - that.panY) < 0.001;
  47       eq &= Math.abs(this.scaleX - that.scaleX) < 0.001;
  48       return !!eq;
  49     },
  50
  51     incrementPanXInViewUnits: function(xDeltaView) {
  52       this.panX += this.xViewVectorToWorld(xDeltaView);
  53     },
  54
  55     xPanWorldPosToViewPos: function(worldX, viewX, viewWidth) {
  56       if (typeof viewX == 'string') {
  57         if (viewX === 'left') {
  58           viewX = 0;
  59         } else if (viewX === 'center') {
  60           viewX = viewWidth / 2;
  61         } else if (viewX === 'right') {
  62           viewX = viewWidth - 1;
  63         } else {
  64           throw new Error('viewX must be left|center|right or number.');
  65         }
  66       }
  67       this.panX = (viewX / this.scaleX) - worldX;
  68     },
  69
  70     xPanWorldBoundsIntoView: function(worldMin, worldMax, viewWidth) {
  71       if (this.xWorldToView(worldMin) < 0)
  72         this.xPanWorldPosToViewPos(worldMin, 'left', viewWidth);
  73       else if (this.xWorldToView(worldMax) > viewWidth)
  74         this.xPanWorldPosToViewPos(worldMax, 'right', viewWidth);
  75     },
  76
  77     xSetWorldBounds: function(worldMin, worldMax, viewWidth) {
  78       var worldWidth = worldMax - worldMin;
  79       var scaleX = viewWidth / worldWidth;
  80       var panX = -worldMin;
  81       this.setPanAndScale(panX, scaleX);
  82     },
  83
  84     setPanAndScale: function(p, s) {
  85       this.scaleX = s;
  86       this.panX = p;
  87     },
  88
  89     xWorldToView: function(x) {
  90       return (x + this.panX) * this.scaleX;
  91     },
  92
  93     xWorldVectorToView: function(x) {
  94       return x * this.scaleX;
  95     },
  96
  97     xViewToWorld: function(x) {
  98       return (x / this.scaleX) - this.panX;
  99     },
 100
 101     xViewVectorToWorld: function(x) {
 102       return x / this.scaleX;
 103     },
 104
 105     applyTransformToCanvas: function(ctx) {
 106       ctx.transform(this.scaleX, 0, 0, 1, this.panX * this.scaleX, 0);
 107     }
 108   };
 109
 110   return {
 111     TimelineDisplayTransform: TimelineDisplayTransform
 112   };
 113 });