All files / lib/display display.js

0% Statements 0/110
0% Branches 0/39
0% Functions 0/20
0% Lines 0/107

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     
import LinearScale from '../util/linear-scale.js'
 
export default class Display {
  constructor(transitive) {
    this.transitive = transitive
 
    this.zoomFactors =
      transitive.options.zoomFactors || this.getDefaultZoomFactors()
 
    this.updateActiveZoomFactors(1)
  }
 
  setDimensions(width, height) {
    this.width = width
    this.height = height
  }
 
  setXDomain(domain) {
    // [minX , maxX]
    this.xDomain = domain
    this.xScale = new LinearScale(domain, [0, this.width])
    if (!this.initialXDomain) {
      this.initialXDomain = domain
      this.initialXRes = (domain[1] - domain[0]) / this.width
    }
  }
 
  setYDomain(domain) {
    // [minY , maxY]
    this.yDomain = domain
    this.yScale = new LinearScale(domain, [this.height, 0])
    if (!this.initialYDomain) this.initialYDomain = domain
  }
 
  fitToWorldBounds(bounds) {
    const domains = this.computeDomainsFromBounds(bounds)
    this.setXDomain(domains[0])
    this.setYDomain(domains[1])
    this.computeScale()
  }
 
  reset() {
    this.initialXDomain = null
    this.initialYDomain = null
    this.scaleSet = false
    this.lastScale = undefined
  }
 
  /**
   * Apply a transformation {x, y, k} to the *initial* state of the map, where
   * (x, y) is the pixel offset and k is a scale factor relative to an initial
   * zoom level of 1.0. Intended primarily to support D3-style panning/zooming.
   */
 
  applyTransform(transform) {
    const { k, x, y } = transform
 
    let xMin = this.initialXDomain[0]
    let xMax = this.initialXDomain[1]
    let yMin = this.initialYDomain[0]
    let yMax = this.initialYDomain[1]
 
    // Apply the scale factor
    xMax = xMin + (xMax - xMin) / k
    yMin = yMax - (yMax - yMin) / k
 
    // Apply the translation
    const xOffset = (-x * (xMax - xMin)) / this.width
    xMin += xOffset
    xMax += xOffset
    const yOffset = (y * (yMax - yMin)) / this.height
    yMin += yOffset
    yMax += yOffset
 
    // Update the scale functions and recompute the internal scale factor
    this.setXDomain([xMin, xMax])
    this.setYDomain([yMin, yMax])
    this.computeScale()
  }
 
  getDefaultZoomFactors(data) {
    return [
      {
        angleConstraint: 45,
        gridCellSize: 25,
        internalVertexFactor: 1000000,
        mergeVertexThreshold: 200,
        minScale: 0
      },
      {
        angleConstraint: 5,
        gridCellSize: 0,
        internalVertexFactor: 0,
        mergeVertexThreshold: 0,
        minScale: 1.5
      }
    ]
  }
 
  updateActiveZoomFactors(scale) {
    let updated = false
    for (let i = 0; i < this.zoomFactors.length; i++) {
      const min = this.zoomFactors[i].minScale
      const max =
        i < this.zoomFactors.length - 1
          ? this.zoomFactors[i + 1].minScale
          : Number.MAX_VALUE
 
      // check if we've crossed into a new zoomFactor partition
      if (
        (!this.lastScale || this.lastScale < min || this.lastScale >= max) &&
        scale >= min &&
        scale < max
      ) {
        this.activeZoomFactors = this.zoomFactors[i]
        updated = true
      }
    }
    return updated
  }
 
  computeScale() {
    this.lastScale = this.scale
    this.scaleSet = true
    const newXRes = (this.xDomain[1] - this.xDomain[0]) / this.width
    this.scale = this.initialXRes / newXRes
    if (this.lastScale !== this.scale) this.scaleChanged()
  }
 
  scaleChanged() {
    const zoomFactorsChanged = this.updateActiveZoomFactors(this.scale)
    if (zoomFactorsChanged) {
      this.transitive.network = null
      this.transitive.render()
    }
  }
 
  /**
   * Compute the x/y coordinate space domains to fit the graph.
   */
 
  computeDomainsFromBounds(bounds) {
    const xmin = bounds[0][0]
    const xmax = bounds[1][0]
    const ymin = bounds[0][1]
    const ymax = bounds[1][1]
    const xRange = xmax - xmin
    const yRange = ymax - ymin
 
    const { options } = this.transitive
 
    const paddingFactor =
      options && options.paddingFactor ? options.paddingFactor : 0.1
 
    const margins = this.getMargins()
 
    const usableHeight = this.height - margins.top - margins.bottom
    const usableWidth = this.width - margins.left - margins.right
    const displayAspect = this.width / this.height
    const usableDisplayAspect = usableWidth / usableHeight
    const graphAspect = xRange / (yRange === 0 ? -Infinity : yRange)
 
    let padding
    let dispX1, dispX2, dispY1, dispY2
    let dispXRange, dispYRange
 
    if (usableDisplayAspect > graphAspect) {
      // y-axis is limiting
      padding = paddingFactor * yRange
      dispY1 = ymin - padding
      dispY2 = ymax + padding
      dispYRange = yRange + 2 * padding
      const addedYRange = (this.height / usableHeight) * dispYRange - dispYRange
      if (margins.top > 0 || margins.bottom > 0) {
        dispY1 -=
          (margins.bottom / (margins.bottom + margins.top)) * addedYRange
        dispY2 += (margins.top / (margins.bottom + margins.top)) * addedYRange
      }
      dispXRange = (dispY2 - dispY1) * displayAspect
      const xOffset = (margins.left - margins.right) / this.width
      const xMidpoint = (xmax + xmin - dispXRange * xOffset) / 2
      dispX1 = xMidpoint - dispXRange / 2
      dispX2 = xMidpoint + dispXRange / 2
    } else {
      // x-axis limiting
      padding = paddingFactor * xRange
      dispX1 = xmin - padding
      dispX2 = xmax + padding
      dispXRange = xRange + 2 * padding
      const addedXRange = (this.width / usableWidth) * dispXRange - dispXRange
      if (margins.left > 0 || margins.right > 0) {
        dispX1 -= (margins.left / (margins.left + margins.right)) * addedXRange
        dispX2 += (margins.right / (margins.left + margins.right)) * addedXRange
      }
 
      dispYRange = (dispX2 - dispX1) / displayAspect
      const yOffset = (margins.bottom - margins.top) / this.height
      const yMidpoint = (ymax + ymin - dispYRange * yOffset) / 2
      dispY1 = yMidpoint - dispYRange / 2
      dispY2 = yMidpoint + dispYRange / 2
    }
 
    return [
      [dispX1, dispX2],
      [dispY1, dispY2]
    ]
  }
 
  getMargins() {
    return Object.assign(
      {
        bottom: 0,
        left: 0,
        right: 0,
        top: 0
      },
      this.transitive.options.displayMargins
    )
  }
 
  isInRange(x, y) {
    return x >= 0 && x <= this.width && y >= 0 && y <= this.height
  }
 
  /** Methods to be defined by subclasses **/
 
  clear() {
    throw new Error('method not implemented by subclass!')
  }
 
  drawCircle(coord, attrs) {
    throw new Error('method not implemented by subclass!')
  }
 
  drawEllipse(coord, attrs) {
    throw new Error('method not implemented by subclass!')
  }
 
  drawRect(upperLeft, attrs) {
    throw new Error('method not implemented by subclass!')
  }
 
  drawText(text, anchor, attrs) {
    throw new Error('method not implemented by subclass!')
  }
 
  drawPath(renderData, attrs) {
    throw new Error('method not implemented by subclass!')
  }
}