pdfjs-dist/lib/web/pdf_page_view.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 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.
 *
 * @licend The above is the entire license notice for the
 * Javascript code in this page
 */
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.PDFPageView = void 0;

var _pdf = require("../pdf");

var _ui_utils = require("./ui_utils.js");

var _app_options = require("./app_options.js");

var _l10n_utils = require("./l10n_utils.js");

var _pdf_rendering_queue = require("./pdf_rendering_queue.js");

const MAX_CANVAS_PIXELS = _app_options.compatibilityParams.maxCanvasPixels || 16777216;

class PDFPageView {
  constructor(options) {
    const container = options.container;
    const defaultViewport = options.defaultViewport;
    this.id = options.id;
    this.renderingId = "page" + this.id;
    this.pdfPage = null;
    this.pageLabel = null;
    this.rotation = 0;
    this.scale = options.scale || _ui_utils.DEFAULT_SCALE;
    this.viewport = defaultViewport;
    this.pdfPageRotate = defaultViewport.rotation;
    this._optionalContentConfigPromise = options.optionalContentConfigPromise || null;
    this.hasRestrictedScaling = false;
    this.textLayerMode = options.textLayerMode ?? _ui_utils.TextLayerMode.ENABLE;
    this._annotationMode = options.annotationMode ?? _pdf.AnnotationMode.ENABLE_FORMS;
    this.imageResourcesPath = options.imageResourcesPath || "";
    this.useOnlyCssZoom = options.useOnlyCssZoom || false;
    this.maxCanvasPixels = options.maxCanvasPixels || MAX_CANVAS_PIXELS;
    this.eventBus = options.eventBus;
    this.renderingQueue = options.renderingQueue;
    this.textLayerFactory = options.textLayerFactory;
    this.annotationLayerFactory = options.annotationLayerFactory;
    this.xfaLayerFactory = options.xfaLayerFactory;
    this.textHighlighter = options.textHighlighterFactory?.createTextHighlighter(this.id - 1, this.eventBus);
    this.structTreeLayerFactory = options.structTreeLayerFactory;
    this.renderer = options.renderer || _ui_utils.RendererType.CANVAS;
    this.l10n = options.l10n || _l10n_utils.NullL10n;
    this.paintTask = null;
    this.paintedViewportMap = new WeakMap();
    this.renderingState = _pdf_rendering_queue.RenderingStates.INITIAL;
    this.resume = null;
    this._renderError = null;
    this._isStandalone = !this.renderingQueue?.hasViewer();
    this.annotationLayer = null;
    this.textLayer = null;
    this.zoomLayer = null;
    this.xfaLayer = null;
    this.structTreeLayer = null;
    const 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);
    div.setAttribute("role", "region");
    this.l10n.get("page_landmark", {
      page: this.id
    }).then(msg => {
      div.setAttribute("aria-label", msg);
    });
    this.div = div;
    container.appendChild(div);
  }

  setPdfPage(pdfPage) {
    this.pdfPage = pdfPage;
    this.pdfPageRotate = pdfPage.rotate;
    const totalRotation = (this.rotation + this.pdfPageRotate) % 360;
    this.viewport = pdfPage.getViewport({
      scale: this.scale * _pdf.PixelsPerInch.PDF_TO_CSS_UNITS,
      rotation: totalRotation
    });
    this.reset();
  }

  destroy() {
    this.reset();

    if (this.pdfPage) {
      this.pdfPage.cleanup();
    }
  }

  async _renderAnnotationLayer() {
    let error = null;

    try {
      await this.annotationLayer.render(this.viewport, "display");
    } catch (ex) {
      error = ex;
    } finally {
      this.eventBus.dispatch("annotationlayerrendered", {
        source: this,
        pageNumber: this.id,
        error
      });
    }
  }

  async _renderXfaLayer() {
    let error = null;

    try {
      const result = await this.xfaLayer.render(this.viewport, "display");

      if (this.textHighlighter) {
        this._buildXfaTextContentItems(result.textDivs);
      }
    } catch (ex) {
      error = ex;
    } finally {
      this.eventBus.dispatch("xfalayerrendered", {
        source: this,
        pageNumber: this.id,
        error
      });
    }
  }

  async _buildXfaTextContentItems(textDivs) {
    const text = await this.pdfPage.getTextContent();
    const items = [];

    for (const item of text.items) {
      items.push(item.str);
    }

    this.textHighlighter.setTextMapping(textDivs, items);
    this.textHighlighter.enable();
  }

  _resetZoomLayer(removeFromDOM = false) {
    if (!this.zoomLayer) {
      return;
    }

    const zoomLayerCanvas = this.zoomLayer.firstChild;
    this.paintedViewportMap.delete(zoomLayerCanvas);
    zoomLayerCanvas.width = 0;
    zoomLayerCanvas.height = 0;

    if (removeFromDOM) {
      this.zoomLayer.remove();
    }

    this.zoomLayer = null;
  }

  reset({
    keepZoomLayer = false,
    keepAnnotationLayer = false,
    keepXfaLayer = false
  } = {}) {
    this.cancelRendering({
      keepAnnotationLayer,
      keepXfaLayer
    });
    this.renderingState = _pdf_rendering_queue.RenderingStates.INITIAL;
    const div = this.div;
    div.style.width = Math.floor(this.viewport.width) + "px";
    div.style.height = Math.floor(this.viewport.height) + "px";
    const childNodes = div.childNodes,
          zoomLayerNode = keepZoomLayer && this.zoomLayer || null,
          annotationLayerNode = keepAnnotationLayer && this.annotationLayer?.div || null,
          xfaLayerNode = keepXfaLayer && this.xfaLayer?.div || null;

    for (let i = childNodes.length - 1; i >= 0; i--) {
      const node = childNodes[i];

      switch (node) {
        case zoomLayerNode:
        case annotationLayerNode:
        case xfaLayerNode:
          continue;
      }

      div.removeChild(node);
    }

    div.removeAttribute("data-loaded");

    if (annotationLayerNode) {
      this.annotationLayer.hide();
    }

    if (xfaLayerNode) {
      this.xfaLayer.hide();
    }

    if (!zoomLayerNode) {
      if (this.canvas) {
        this.paintedViewportMap.delete(this.canvas);
        this.canvas.width = 0;
        this.canvas.height = 0;
        delete this.canvas;
      }

      this._resetZoomLayer();
    }

    if (this.svg) {
      this.paintedViewportMap.delete(this.svg);
      delete this.svg;
    }

    this.loadingIconDiv = document.createElement("div");
    this.loadingIconDiv.className = "loadingIcon";
    this.loadingIconDiv.setAttribute("role", "img");
    this.l10n.get("loading").then(msg => {
      this.loadingIconDiv?.setAttribute("aria-label", msg);
    });
    div.appendChild(this.loadingIconDiv);
  }

  update({
    scale = 0,
    rotation = null,
    optionalContentConfigPromise = null
  }) {
    if (typeof arguments[0] !== "object") {
      console.error("PDFPageView.update called with separate parameters, please use an object instead.");
      this.update({
        scale: arguments[0],
        rotation: arguments[1],
        optionalContentConfigPromise: arguments[2]
      });
      return;
    }

    this.scale = scale || this.scale;

    if (typeof rotation === "number") {
      this.rotation = rotation;
    }

    if (optionalContentConfigPromise instanceof Promise) {
      this._optionalContentConfigPromise = optionalContentConfigPromise;
    }

    if (this._isStandalone) {
      const doc = document.documentElement;
      doc.style.setProperty("--zoom-factor", this.scale);
    }

    const totalRotation = (this.rotation + this.pdfPageRotate) % 360;
    this.viewport = this.viewport.clone({
      scale: this.scale * _pdf.PixelsPerInch.PDF_TO_CSS_UNITS,
      rotation: totalRotation
    });

    if (this.svg) {
      this.cssTransform({
        target: this.svg,
        redrawAnnotationLayer: true,
        redrawXfaLayer: true
      });
      this.eventBus.dispatch("pagerendered", {
        source: this,
        pageNumber: this.id,
        cssTransform: true,
        timestamp: performance.now(),
        error: this._renderError
      });
      return;
    }

    let isScalingRestricted = false;

    if (this.canvas && this.maxCanvasPixels > 0) {
      const outputScale = this.outputScale;

      if ((Math.floor(this.viewport.width) * outputScale.sx | 0) * (Math.floor(this.viewport.height) * outputScale.sy | 0) > this.maxCanvasPixels) {
        isScalingRestricted = true;
      }
    }

    if (this.canvas) {
      if (this.useOnlyCssZoom || this.hasRestrictedScaling && isScalingRestricted) {
        this.cssTransform({
          target: this.canvas,
          redrawAnnotationLayer: true,
          redrawXfaLayer: true
        });
        this.eventBus.dispatch("pagerendered", {
          source: this,
          pageNumber: this.id,
          cssTransform: true,
          timestamp: performance.now(),
          error: this._renderError
        });
        return;
      }

      if (!this.zoomLayer && !this.canvas.hidden) {
        this.zoomLayer = this.canvas.parentNode;
        this.zoomLayer.style.position = "absolute";
      }
    }

    if (this.zoomLayer) {
      this.cssTransform({
        target: this.zoomLayer.firstChild
      });
    }

    this.reset({
      keepZoomLayer: true,
      keepAnnotationLayer: true,
      keepXfaLayer: true
    });
  }

  cancelRendering({
    keepAnnotationLayer = false,
    keepXfaLayer = false
  } = {}) {
    if (this.paintTask) {
      this.paintTask.cancel();
      this.paintTask = null;
    }

    this.resume = null;

    if (this.textLayer) {
      this.textLayer.cancel();
      this.textLayer = null;
    }

    if (this.annotationLayer && (!keepAnnotationLayer || !this.annotationLayer.div)) {
      this.annotationLayer.cancel();
      this.annotationLayer = null;
    }

    if (this.xfaLayer && (!keepXfaLayer || !this.xfaLayer.div)) {
      this.xfaLayer.cancel();
      this.xfaLayer = null;
      this.textHighlighter?.disable();
    }

    if (this._onTextLayerRendered) {
      this.eventBus._off("textlayerrendered", this._onTextLayerRendered);

      this._onTextLayerRendered = null;
    }
  }

  cssTransform({
    target,
    redrawAnnotationLayer = false,
    redrawXfaLayer = false
  }) {
    const width = this.viewport.width;
    const height = this.viewport.height;
    const 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";
    const relativeRotation = this.viewport.rotation - this.paintedViewportMap.get(target).rotation;
    const absRotation = Math.abs(relativeRotation);
    let scaleX = 1,
        scaleY = 1;

    if (absRotation === 90 || absRotation === 270) {
      scaleX = height / width;
      scaleY = width / height;
    }

    target.style.transform = `rotate(${relativeRotation}deg) scale(${scaleX}, ${scaleY})`;

    if (this.textLayer) {
      const textLayerViewport = this.textLayer.viewport;
      const textRelativeRotation = this.viewport.rotation - textLayerViewport.rotation;
      const textAbsRotation = Math.abs(textRelativeRotation);
      let scale = width / textLayerViewport.width;

      if (textAbsRotation === 90 || textAbsRotation === 270) {
        scale = width / textLayerViewport.height;
      }

      const textLayerDiv = this.textLayer.textLayerDiv;
      let 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;
      }

      textLayerDiv.style.transform = `rotate(${textAbsRotation}deg) ` + `scale(${scale}) ` + `translate(${transX}, ${transY})`;
      textLayerDiv.style.transformOrigin = "0% 0%";
    }

    if (redrawAnnotationLayer && this.annotationLayer) {
      this._renderAnnotationLayer();
    }

    if (redrawXfaLayer && this.xfaLayer) {
      this._renderXfaLayer();
    }
  }

  get width() {
    return this.viewport.width;
  }

  get height() {
    return this.viewport.height;
  }

  getPagePoint(x, y) {
    return this.viewport.convertToPdfPoint(x, y);
  }

  draw() {
    if (this.renderingState !== _pdf_rendering_queue.RenderingStates.INITIAL) {
      console.error("Must be in new state before drawing");
      this.reset();
    }

    const {
      div,
      pdfPage
    } = this;

    if (!pdfPage) {
      this.renderingState = _pdf_rendering_queue.RenderingStates.FINISHED;

      if (this.loadingIconDiv) {
        div.removeChild(this.loadingIconDiv);
        delete this.loadingIconDiv;
      }

      return Promise.reject(new Error("pdfPage is not loaded"));
    }

    this.renderingState = _pdf_rendering_queue.RenderingStates.RUNNING;
    const canvasWrapper = document.createElement("div");
    canvasWrapper.style.width = div.style.width;
    canvasWrapper.style.height = div.style.height;
    canvasWrapper.classList.add("canvasWrapper");

    if (this.annotationLayer?.div) {
      div.insertBefore(canvasWrapper, this.annotationLayer.div);
    } else {
      div.appendChild(canvasWrapper);
    }

    let textLayer = null;

    if (this.textLayerMode !== _ui_utils.TextLayerMode.DISABLE && this.textLayerFactory) {
      const textLayerDiv = document.createElement("div");
      textLayerDiv.className = "textLayer";
      textLayerDiv.style.width = canvasWrapper.style.width;
      textLayerDiv.style.height = canvasWrapper.style.height;

      if (this.annotationLayer?.div) {
        div.insertBefore(textLayerDiv, this.annotationLayer.div);
      } else {
        div.appendChild(textLayerDiv);
      }

      textLayer = this.textLayerFactory.createTextLayerBuilder(textLayerDiv, this.id - 1, this.viewport, this.textLayerMode === _ui_utils.TextLayerMode.ENABLE_ENHANCE, this.eventBus, this.textHighlighter);
    }

    this.textLayer = textLayer;

    if (this.xfaLayer?.div) {
      div.appendChild(this.xfaLayer.div);
    }

    let renderContinueCallback = null;

    if (this.renderingQueue) {
      renderContinueCallback = cont => {
        if (!this.renderingQueue.isHighestPriority(this)) {
          this.renderingState = _pdf_rendering_queue.RenderingStates.PAUSED;

          this.resume = () => {
            this.renderingState = _pdf_rendering_queue.RenderingStates.RUNNING;
            cont();
          };

          return;
        }

        cont();
      };
    }

    const finishPaintTask = async (error = null) => {
      if (paintTask === this.paintTask) {
        this.paintTask = null;
      }

      if (error instanceof _pdf.RenderingCancelledException) {
        this._renderError = null;
        return;
      }

      this._renderError = error;
      this.renderingState = _pdf_rendering_queue.RenderingStates.FINISHED;

      if (this.loadingIconDiv) {
        div.removeChild(this.loadingIconDiv);
        delete this.loadingIconDiv;
      }

      this._resetZoomLayer(true);

      this.eventBus.dispatch("pagerendered", {
        source: this,
        pageNumber: this.id,
        cssTransform: false,
        timestamp: performance.now(),
        error: this._renderError
      });

      if (error) {
        throw error;
      }
    };

    const paintTask = this.renderer === _ui_utils.RendererType.SVG ? this.paintOnSvg(canvasWrapper) : this.paintOnCanvas(canvasWrapper);
    paintTask.onRenderContinue = renderContinueCallback;
    this.paintTask = paintTask;
    const resultPromise = paintTask.promise.then(() => {
      return finishPaintTask(null).then(() => {
        if (textLayer) {
          const readableStream = pdfPage.streamTextContent({
            normalizeWhitespace: true,
            includeMarkedContent: true
          });
          textLayer.setTextContentStream(readableStream);
          textLayer.render();
        }
      });
    }, function (reason) {
      return finishPaintTask(reason);
    });

    if (this._annotationMode !== _pdf.AnnotationMode.DISABLE && this.annotationLayerFactory) {
      if (!this.annotationLayer) {
        this.annotationLayer = this.annotationLayerFactory.createAnnotationLayerBuilder(div, pdfPage, null, this.imageResourcesPath, this._annotationMode === _pdf.AnnotationMode.ENABLE_FORMS, this.l10n, null, null, null, null);
      }

      this._renderAnnotationLayer();
    }

    if (this.xfaLayerFactory) {
      if (!this.xfaLayer) {
        this.xfaLayer = this.xfaLayerFactory.createXfaLayerBuilder(div, pdfPage, null);
      }

      this._renderXfaLayer();
    }

    if (this.structTreeLayerFactory && this.textLayer && this.canvas) {
      this._onTextLayerRendered = event => {
        if (event.pageNumber !== this.id) {
          return;
        }

        this.eventBus._off("textlayerrendered", this._onTextLayerRendered);

        this._onTextLayerRendered = null;

        if (!this.canvas) {
          return;
        }

        this.pdfPage.getStructTree().then(tree => {
          if (!tree) {
            return;
          }

          if (!this.canvas) {
            return;
          }

          const treeDom = this.structTreeLayer.render(tree);
          treeDom.classList.add("structTree");
          this.canvas.appendChild(treeDom);
        });
      };

      this.eventBus._on("textlayerrendered", this._onTextLayerRendered);

      this.structTreeLayer = this.structTreeLayerFactory.createStructTreeLayerBuilder(pdfPage);
    }

    div.setAttribute("data-loaded", true);
    this.eventBus.dispatch("pagerender", {
      source: this,
      pageNumber: this.id
    });
    return resultPromise;
  }

  paintOnCanvas(canvasWrapper) {
    const renderCapability = (0, _pdf.createPromiseCapability)();
    const result = {
      promise: renderCapability.promise,

      onRenderContinue(cont) {
        cont();
      },

      cancel() {
        renderTask.cancel();
      }

    };
    const viewport = this.viewport;
    const canvas = document.createElement("canvas");
    canvas.hidden = true;
    let isCanvasHidden = true;

    const showCanvas = function () {
      if (isCanvasHidden) {
        canvas.hidden = false;
        isCanvasHidden = false;
      }
    };

    canvasWrapper.appendChild(canvas);
    this.canvas = canvas;
    canvas.mozOpaque = true;
    const ctx = canvas.getContext("2d", {
      alpha: false
    });
    const outputScale = (0, _ui_utils.getOutputScale)(ctx);
    this.outputScale = outputScale;

    if (this.useOnlyCssZoom) {
      const actualSizeViewport = viewport.clone({
        scale: _pdf.PixelsPerInch.PDF_TO_CSS_UNITS
      });
      outputScale.sx *= actualSizeViewport.width / viewport.width;
      outputScale.sy *= actualSizeViewport.height / viewport.height;
      outputScale.scaled = true;
    }

    if (this.maxCanvasPixels > 0) {
      const pixelsInViewport = viewport.width * viewport.height;
      const maxScale = Math.sqrt(this.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;
      }
    }

    const sfx = (0, _ui_utils.approximateFraction)(outputScale.sx);
    const sfy = (0, _ui_utils.approximateFraction)(outputScale.sy);
    canvas.width = (0, _ui_utils.roundToDivide)(viewport.width * outputScale.sx, sfx[0]);
    canvas.height = (0, _ui_utils.roundToDivide)(viewport.height * outputScale.sy, sfy[0]);
    canvas.style.width = (0, _ui_utils.roundToDivide)(viewport.width, sfx[1]) + "px";
    canvas.style.height = (0, _ui_utils.roundToDivide)(viewport.height, sfy[1]) + "px";
    this.paintedViewportMap.set(canvas, viewport);
    const transform = !outputScale.scaled ? null : [outputScale.sx, 0, 0, outputScale.sy, 0, 0];
    const renderContext = {
      canvasContext: ctx,
      transform,
      viewport: this.viewport,
      annotationMode: this._annotationMode,
      optionalContentConfigPromise: this._optionalContentConfigPromise
    };
    const renderTask = this.pdfPage.render(renderContext);

    renderTask.onContinue = function (cont) {
      showCanvas();

      if (result.onRenderContinue) {
        result.onRenderContinue(cont);
      } else {
        cont();
      }
    };

    renderTask.promise.then(function () {
      showCanvas();
      renderCapability.resolve(undefined);
    }, function (error) {
      showCanvas();
      renderCapability.reject(error);
    });
    return result;
  }

  paintOnSvg(wrapper) {
    let cancelled = false;

    const ensureNotCancelled = () => {
      if (cancelled) {
        throw new _pdf.RenderingCancelledException(`Rendering cancelled, page ${this.id}`, "svg");
      }
    };

    const pdfPage = this.pdfPage;
    const actualSizeViewport = this.viewport.clone({
      scale: _pdf.PixelsPerInch.PDF_TO_CSS_UNITS
    });
    const promise = pdfPage.getOperatorList({
      annotationMode: this._annotationMode
    }).then(opList => {
      ensureNotCancelled();
      const svgGfx = new _pdf.SVGGraphics(pdfPage.commonObjs, pdfPage.objs, _app_options.compatibilityParams.disableCreateObjectURL);
      return svgGfx.getSVG(opList, actualSizeViewport).then(svg => {
        ensureNotCancelled();
        this.svg = svg;
        this.paintedViewportMap.set(svg, actualSizeViewport);
        svg.style.width = wrapper.style.width;
        svg.style.height = wrapper.style.height;
        this.renderingState = _pdf_rendering_queue.RenderingStates.FINISHED;
        wrapper.appendChild(svg);
      });
    });
    return {
      promise,

      onRenderContinue(cont) {
        cont();
      },

      cancel() {
        cancelled = true;
      }

    };
  }

  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");
    }
  }

}

exports.PDFPageView = PDFPageView;