pdfjs-dist/lib/web/pdf_page_view.js

/* Copyright 2017 Mozilla Foundation
 *
 * Licensed 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.
 */
'use strict';

var uiUtils = require('./ui_utils.js');
var pdfRenderingQueue = require('./pdf_rendering_queue.js');
var domEvents = require('./dom_events.js');
var pdfjsLib = require('./pdfjs.js');
var CSS_UNITS = uiUtils.CSS_UNITS;
var DEFAULT_SCALE = uiUtils.DEFAULT_SCALE;
var getOutputScale = uiUtils.getOutputScale;
var approximateFraction = uiUtils.approximateFraction;
var roundToDivide = uiUtils.roundToDivide;
var RendererType = uiUtils.RendererType;
var RenderingStates = pdfRenderingQueue.RenderingStates;
var TEXT_LAYER_RENDER_DELAY = 200;
var PDFPageView = function PDFPageViewClosure() {
  function PDFPageView(options) {
    var container = options.container;
    var id = options.id;
    var scale = options.scale;
    var defaultViewport = options.defaultViewport;
    var renderingQueue = options.renderingQueue;
    var textLayerFactory = options.textLayerFactory;
    var annotationLayerFactory = options.annotationLayerFactory;
    var enhanceTextSelection = options.enhanceTextSelection || false;
    var renderInteractiveForms = options.renderInteractiveForms || false;
    this.id = id;
    this.renderingId = 'page' + id;
    this.pageLabel = null;
    this.rotation = 0;
    this.scale = scale || DEFAULT_SCALE;
    this.viewport = defaultViewport;
    this.pdfPageRotate = defaultViewport.rotation;
    this.hasRestrictedScaling = false;
    this.enhanceTextSelection = enhanceTextSelection;
    this.renderInteractiveForms = renderInteractiveForms;
    this.eventBus = options.eventBus || domEvents.getGlobalEventBus();
    this.renderingQueue = renderingQueue;
    this.textLayerFactory = textLayerFactory;
    this.annotationLayerFactory = annotationLayerFactory;
    this.renderer = options.renderer || RendererType.CANVAS;
    this.paintTask = null;
    this.paintedViewportMap = new WeakMap();
    this.renderingState = RenderingStates.INITIAL;
    this.resume = null;
    this.error = null;
    this.onBeforeDraw = null;
    this.onAfterDraw = null;
    this.textLayer = null;
    this.zoomLayer = null;
    this.annotationLayer = null;
    var div = document.createElement('div');
    div.className = 'page';
    div.style.width = Math.floor(this.viewport.width) + 'px';
    div.style.height = Math.floor(this.viewport.height) + 'px';
    div.setAttribute('data-page-number', this.id);
    this.div = div;
    container.appendChild(div);
  }
  PDFPageView.prototype = {
    setPdfPage: function PDFPageView_setPdfPage(pdfPage) {
      this.pdfPage = pdfPage;
      this.pdfPageRotate = pdfPage.rotate;
      var totalRotation = (this.rotation + this.pdfPageRotate) % 360;
      this.viewport = pdfPage.getViewport(this.scale * CSS_UNITS, totalRotation);
      this.stats = pdfPage.stats;
      this.reset();
    },
    destroy: function PDFPageView_destroy() {
      this.zoomLayer = null;
      this.reset();
      if (this.pdfPage) {
        this.pdfPage.cleanup();
      }
    },
    reset: function PDFPageView_reset(keepZoomLayer, keepAnnotations) {
      this.cancelRendering();
      var div = this.div;
      div.style.width = Math.floor(this.viewport.width) + 'px';
      div.style.height = Math.floor(this.viewport.height) + 'px';
      var childNodes = div.childNodes;
      var currentZoomLayerNode = keepZoomLayer && this.zoomLayer || null;
      var currentAnnotationNode = keepAnnotations && this.annotationLayer && this.annotationLayer.div || null;
      for (var i = childNodes.length - 1; i >= 0; i--) {
        var node = childNodes[i];
        if (currentZoomLayerNode === node || currentAnnotationNode === node) {
          continue;
        }
        div.removeChild(node);
      }
      div.removeAttribute('data-loaded');
      if (currentAnnotationNode) {
        this.annotationLayer.hide();
      } else {
        this.annotationLayer = null;
      }
      if (this.canvas && !currentZoomLayerNode) {
        this.paintedViewportMap.delete(this.canvas);
        this.canvas.width = 0;
        this.canvas.height = 0;
        delete this.canvas;
      }
      if (this.svg) {
        this.paintedViewportMap.delete(this.svg);
        delete this.svg;
      }
      this.loadingIconDiv = document.createElement('div');
      this.loadingIconDiv.className = 'loadingIcon';
      div.appendChild(this.loadingIconDiv);
    },
    update: function PDFPageView_update(scale, rotation) {
      this.scale = scale || this.scale;
      if (typeof rotation !== 'undefined') {
        this.rotation = rotation;
      }
      var totalRotation = (this.rotation + this.pdfPageRotate) % 360;
      this.viewport = this.viewport.clone({
        scale: this.scale * CSS_UNITS,
        rotation: totalRotation
      });
      if (this.svg) {
        this.cssTransform(this.svg, true);
        this.eventBus.dispatch('pagerendered', {
          source: this,
          pageNumber: this.id,
          cssTransform: true
        });
        return;
      }
      var isScalingRestricted = false;
      if (this.canvas && pdfjsLib.PDFJS.maxCanvasPixels > 0) {
        var outputScale = this.outputScale;
        if ((Math.floor(this.viewport.width) * outputScale.sx | 0) * (Math.floor(this.viewport.height) * outputScale.sy | 0) > pdfjsLib.PDFJS.maxCanvasPixels) {
          isScalingRestricted = true;
        }
      }
      if (this.canvas) {
        if (pdfjsLib.PDFJS.useOnlyCssZoom || this.hasRestrictedScaling && isScalingRestricted) {
          this.cssTransform(this.canvas, true);
          this.eventBus.dispatch('pagerendered', {
            source: this,
            pageNumber: this.id,
            cssTransform: true
          });
          return;
        }
        if (!this.zoomLayer) {
          this.zoomLayer = this.canvas.parentNode;
          this.zoomLayer.style.position = 'absolute';
        }
      }
      if (this.zoomLayer) {
        this.cssTransform(this.zoomLayer.firstChild);
      }
      this.reset(true, true);
    },
    cancelRendering: function PDFPageView_cancelRendering() {
      if (this.paintTask) {
        this.paintTask.cancel();
        this.paintTask = null;
      }
      this.renderingState = RenderingStates.INITIAL;
      this.resume = null;
      if (this.textLayer) {
        this.textLayer.cancel();
        this.textLayer = null;
      }
    },
    updatePosition: function PDFPageView_updatePosition() {
      if (this.textLayer) {
        this.textLayer.render(TEXT_LAYER_RENDER_DELAY);
      }
    },
    cssTransform: function PDFPageView_transform(target, redrawAnnotations) {
      var CustomStyle = pdfjsLib.CustomStyle;
      var width = this.viewport.width;
      var height = this.viewport.height;
      var div = this.div;
      target.style.width = target.parentNode.style.width = div.style.width = Math.floor(width) + 'px';
      target.style.height = target.parentNode.style.height = div.style.height = Math.floor(height) + 'px';
      var relativeRotation = this.viewport.rotation - this.paintedViewportMap.get(target).rotation;
      var absRotation = Math.abs(relativeRotation);
      var scaleX = 1,
          scaleY = 1;
      if (absRotation === 90 || absRotation === 270) {
        scaleX = height / width;
        scaleY = width / height;
      }
      var cssTransform = 'rotate(' + relativeRotation + 'deg) ' + 'scale(' + scaleX + ',' + scaleY + ')';
      CustomStyle.setProp('transform', target, cssTransform);
      if (this.textLayer) {
        var textLayerViewport = this.textLayer.viewport;
        var textRelativeRotation = this.viewport.rotation - textLayerViewport.rotation;
        var textAbsRotation = Math.abs(textRelativeRotation);
        var scale = width / textLayerViewport.width;
        if (textAbsRotation === 90 || textAbsRotation === 270) {
          scale = width / textLayerViewport.height;
        }
        var textLayerDiv = this.textLayer.textLayerDiv;
        var transX, transY;
        switch (textAbsRotation) {
          case 0:
            transX = transY = 0;
            break;
          case 90:
            transX = 0;
            transY = '-' + textLayerDiv.style.height;
            break;
          case 180:
            transX = '-' + textLayerDiv.style.width;
            transY = '-' + textLayerDiv.style.height;
            break;
          case 270:
            transX = '-' + textLayerDiv.style.width;
            transY = 0;
            break;
          default:
            console.error('Bad rotation value.');
            break;
        }
        CustomStyle.setProp('transform', textLayerDiv, 'rotate(' + textAbsRotation + 'deg) ' + 'scale(' + scale + ', ' + scale + ') ' + 'translate(' + transX + ', ' + transY + ')');
        CustomStyle.setProp('transformOrigin', textLayerDiv, '0% 0%');
      }
      if (redrawAnnotations && this.annotationLayer) {
        this.annotationLayer.render(this.viewport, 'display');
      }
    },
    get width() {
      return this.viewport.width;
    },
    get height() {
      return this.viewport.height;
    },
    getPagePoint: function PDFPageView_getPagePoint(x, y) {
      return this.viewport.convertToPdfPoint(x, y);
    },
    draw: function PDFPageView_draw() {
      if (this.renderingState !== RenderingStates.INITIAL) {
        console.error('Must be in new state before drawing');
        this.reset();
      }
      this.renderingState = RenderingStates.RUNNING;
      var self = this;
      var pdfPage = this.pdfPage;
      var div = this.div;
      var canvasWrapper = document.createElement('div');
      canvasWrapper.style.width = div.style.width;
      canvasWrapper.style.height = div.style.height;
      canvasWrapper.classList.add('canvasWrapper');
      if (this.annotationLayer && this.annotationLayer.div) {
        div.insertBefore(canvasWrapper, this.annotationLayer.div);
      } else {
        div.appendChild(canvasWrapper);
      }
      var textLayerDiv = null;
      var textLayer = null;
      if (this.textLayerFactory) {
        textLayerDiv = document.createElement('div');
        textLayerDiv.className = 'textLayer';
        textLayerDiv.style.width = canvasWrapper.style.width;
        textLayerDiv.style.height = canvasWrapper.style.height;
        if (this.annotationLayer && this.annotationLayer.div) {
          div.insertBefore(textLayerDiv, this.annotationLayer.div);
        } else {
          div.appendChild(textLayerDiv);
        }
        textLayer = this.textLayerFactory.createTextLayerBuilder(textLayerDiv, this.id - 1, this.viewport, this.enhanceTextSelection);
      }
      this.textLayer = textLayer;
      var renderContinueCallback = null;
      if (this.renderingQueue) {
        renderContinueCallback = function renderContinueCallback(cont) {
          if (!self.renderingQueue.isHighestPriority(self)) {
            self.renderingState = RenderingStates.PAUSED;
            self.resume = function resumeCallback() {
              self.renderingState = RenderingStates.RUNNING;
              cont();
            };
            return;
          }
          cont();
        };
      }
      var finishPaintTask = function finishPaintTask(error) {
        if (paintTask === self.paintTask) {
          self.paintTask = null;
        }
        if (error === 'cancelled') {
          self.error = null;
          return Promise.resolve(undefined);
        }
        self.renderingState = RenderingStates.FINISHED;
        if (self.loadingIconDiv) {
          div.removeChild(self.loadingIconDiv);
          delete self.loadingIconDiv;
        }
        if (self.zoomLayer) {
          var zoomLayerCanvas = self.zoomLayer.firstChild;
          self.paintedViewportMap.delete(zoomLayerCanvas);
          zoomLayerCanvas.width = 0;
          zoomLayerCanvas.height = 0;
          if (div.contains(self.zoomLayer)) {
            div.removeChild(self.zoomLayer);
          }
          self.zoomLayer = null;
        }
        self.error = error;
        self.stats = pdfPage.stats;
        if (self.onAfterDraw) {
          self.onAfterDraw();
        }
        self.eventBus.dispatch('pagerendered', {
          source: self,
          pageNumber: self.id,
          cssTransform: false
        });
        if (error) {
          return Promise.reject(error);
        }
        return Promise.resolve(undefined);
      };
      var paintTask = this.renderer === RendererType.SVG ? this.paintOnSvg(canvasWrapper) : this.paintOnCanvas(canvasWrapper);
      paintTask.onRenderContinue = renderContinueCallback;
      this.paintTask = paintTask;
      var resultPromise = paintTask.promise.then(function () {
        return finishPaintTask(null).then(function () {
          if (textLayer) {
            pdfPage.getTextContent({ normalizeWhitespace: true }).then(function textContentResolved(textContent) {
              textLayer.setTextContent(textContent);
              textLayer.render(TEXT_LAYER_RENDER_DELAY);
            });
          }
        });
      }, function (reason) {
        return finishPaintTask(reason);
      });
      if (this.annotationLayerFactory) {
        if (!this.annotationLayer) {
          this.annotationLayer = this.annotationLayerFactory.createAnnotationLayerBuilder(div, pdfPage, this.renderInteractiveForms);
        }
        this.annotationLayer.render(this.viewport, 'display');
      }
      div.setAttribute('data-loaded', true);
      if (this.onBeforeDraw) {
        this.onBeforeDraw();
      }
      return resultPromise;
    },
    paintOnCanvas: function (canvasWrapper) {
      var resolveRenderPromise, rejectRenderPromise;
      var promise = new Promise(function (resolve, reject) {
        resolveRenderPromise = resolve;
        rejectRenderPromise = reject;
      });
      var result = {
        promise: promise,
        onRenderContinue: function (cont) {
          cont();
        },
        cancel: function () {
          renderTask.cancel();
        }
      };
      var viewport = this.viewport;
      var canvas = document.createElement('canvas');
      canvas.id = 'page' + this.id;
      canvas.setAttribute('hidden', 'hidden');
      var isCanvasHidden = true;
      var showCanvas = function () {
        if (isCanvasHidden) {
          canvas.removeAttribute('hidden');
          isCanvasHidden = false;
        }
      };
      canvasWrapper.appendChild(canvas);
      this.canvas = canvas;
      canvas.mozOpaque = true;
      var ctx = canvas.getContext('2d', { alpha: false });
      var outputScale = getOutputScale(ctx);
      this.outputScale = outputScale;
      if (pdfjsLib.PDFJS.useOnlyCssZoom) {
        var actualSizeViewport = viewport.clone({ scale: CSS_UNITS });
        outputScale.sx *= actualSizeViewport.width / viewport.width;
        outputScale.sy *= actualSizeViewport.height / viewport.height;
        outputScale.scaled = true;
      }
      if (pdfjsLib.PDFJS.maxCanvasPixels > 0) {
        var pixelsInViewport = viewport.width * viewport.height;
        var maxScale = Math.sqrt(pdfjsLib.PDFJS.maxCanvasPixels / pixelsInViewport);
        if (outputScale.sx > maxScale || outputScale.sy > maxScale) {
          outputScale.sx = maxScale;
          outputScale.sy = maxScale;
          outputScale.scaled = true;
          this.hasRestrictedScaling = true;
        } else {
          this.hasRestrictedScaling = false;
        }
      }
      var sfx = approximateFraction(outputScale.sx);
      var sfy = approximateFraction(outputScale.sy);
      canvas.width = roundToDivide(viewport.width * outputScale.sx, sfx[0]);
      canvas.height = roundToDivide(viewport.height * outputScale.sy, sfy[0]);
      canvas.style.width = roundToDivide(viewport.width, sfx[1]) + 'px';
      canvas.style.height = roundToDivide(viewport.height, sfy[1]) + 'px';
      this.paintedViewportMap.set(canvas, viewport);
      var transform = !outputScale.scaled ? null : [outputScale.sx, 0, 0, outputScale.sy, 0, 0];
      var renderContext = {
        canvasContext: ctx,
        transform: transform,
        viewport: this.viewport,
        renderInteractiveForms: this.renderInteractiveForms
      };
      var renderTask = this.pdfPage.render(renderContext);
      renderTask.onContinue = function (cont) {
        showCanvas();
        if (result.onRenderContinue) {
          result.onRenderContinue(cont);
        } else {
          cont();
        }
      };
      renderTask.promise.then(function pdfPageRenderCallback() {
        showCanvas();
        resolveRenderPromise(undefined);
      }, function pdfPageRenderError(error) {
        showCanvas();
        rejectRenderPromise(error);
      });
      return result;
    },
    paintOnSvg: function PDFPageView_paintOnSvg(wrapper) {
      var cancelled = false;
      var ensureNotCancelled = function () {
        if (cancelled) {
          throw 'cancelled';
        }
      };
      var self = this;
      var pdfPage = this.pdfPage;
      var SVGGraphics = pdfjsLib.SVGGraphics;
      var actualSizeViewport = this.viewport.clone({ scale: CSS_UNITS });
      var promise = pdfPage.getOperatorList().then(function (opList) {
        ensureNotCancelled();
        var svgGfx = new SVGGraphics(pdfPage.commonObjs, pdfPage.objs);
        return svgGfx.getSVG(opList, actualSizeViewport).then(function (svg) {
          ensureNotCancelled();
          self.svg = svg;
          self.paintedViewportMap.set(svg, actualSizeViewport);
          svg.style.width = wrapper.style.width;
          svg.style.height = wrapper.style.height;
          self.renderingState = RenderingStates.FINISHED;
          wrapper.appendChild(svg);
        });
      });
      return {
        promise: promise,
        onRenderContinue: function (cont) {
          cont();
        },
        cancel: function () {
          cancelled = true;
        }
      };
    },
    setPageLabel: function PDFView_setPageLabel(label) {
      this.pageLabel = typeof label === 'string' ? label : null;
      if (this.pageLabel !== null) {
        this.div.setAttribute('data-page-label', this.pageLabel);
      } else {
        this.div.removeAttribute('data-page-label');
      }
    }
  };
  return PDFPageView;
}();
exports.PDFPageView = PDFPageView;