Add supports for view destinations with 'FitR' fit type.

This CL adds supports for navigating to view destinations with fit
type 'FitR' (See table 151 in ISO 32000-1 standard for more details
about syntax of "FitR"), which focus the view on a rectangular window
specified by the FitR's coordinates parameters.

Bug: 55776,535978
Change-Id: I91353e7569830ba306b9d4cc31f32bfb9622c1df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2391735Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: Hui Yingst <nigi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813977}

chrome/browser/resources/pdf/open_pdf_params_parser.js

@@ -4,6 +4,7 @@
 
 import {assert} from 'chrome://resources/js/assert.m.js';
 import {FittingType, NamedDestinationMessageData, Point} from './constants.js';
+import {Size} from './viewport.js';
 
 /**
  * @typedef {{
@@ -27,6 +28,28 @@ export class OpenPdfParamsParser {
   constructor(getNamedDestinationCallback) {
     /** @private {!function(string):!Promise<!NamedDestinationMessageData>} */
     this.getNamedDestinationCallback_ = getNamedDestinationCallback;
+
+    /** @private {!Size} */
+    this.viewportDimensions_;
+  }
+
+  /**
+   * Calculate the zoom level needed for making viewport focus on a rectangular
+   * area in the PDF document.
+   * @param {!Size} size The dimensions of the rectangular area to be focused
+   *     on.
+   * @return {number} The zoom level needed for focusing on the rectangular
+   *     area. A zoom level of 0 indicates that the zoom level cannot be
+   *     calculated with the given information.
+   * @private
+   */
+  calculateRectZoomLevel_(size) {
+    if (size.height === 0 || size.width === 0) {
+      return 0;
+    }
+    return Math.min(
+        this.viewportDimensions_.height / size.height,
+        this.viewportDimensions_.width / size.width);
   }
 
   /**
@@ -129,7 +152,26 @@ export class OpenPdfParamsParser {
     }
 
     if (viewMode === 'fitr' && viewModeComponents.length === 5) {
-      // TODO(crbug.com/535978): Add support for fit type "FitR" in nameddest.
+      assert(this.viewportDimensions_ !== undefined);
+      let x1 = parseFloat(viewModeComponents[1]);
+      let y1 = parseFloat(viewModeComponents[2]);
+      let x2 = parseFloat(viewModeComponents[3]);
+      let y2 = parseFloat(viewModeComponents[4]);
+      if (!Number.isNaN(x1) && !Number.isNaN(y1) && !Number.isNaN(x2) &&
+          !Number.isNaN(y2)) {
+        if (x1 > x2) {
+          [x1, x2] = [x2, x1];
+        }
+        if (y1 > y2) {
+          [y1, y2] = [y2, y1];
+        }
+        const rectSize = {width: x2 - x1, height: y2 - y1};
+        params['position'] = {x: x1, y: y1};
+        const zoom = this.calculateRectZoomLevel_(rectSize);
+        if (zoom !== 0) {
+          params['zoom'] = zoom;
+        }
+      }
       return params;
     }
 
@@ -160,6 +202,14 @@ export class OpenPdfParamsParser {
     return params;
   }
 
+  /**
+   * Store current viewport's dimensions.
+   * @param {!Size} dimensions
+   */
+  setViewportDimensions(dimensions) {
+    this.viewportDimensions_ = dimensions;
+  }
+
   /**
    * @param {string} url that needs to be parsed.
    * @return {boolean} Whether the toolbar UI element should be shown.
@@ -184,7 +234,7 @@ export class OpenPdfParamsParser {
     const urlParams = this.parseUrlParams_(url);
 
     if (urlParams.has('page')) {
-      // |pageNumber| is 1-based, but goToPage() take a zero-based page number.
+      // |pageNumber| is 1-based, but goToPage() take a zero-based page index.
       const pageNumber = parseInt(urlParams.get('page'), 10);
       if (!Number.isNaN(pageNumber) && pageNumber > 0) {
         params['page'] = pageNumber - 1;

chrome/browser/resources/pdf/pdf_viewer_base.js

@@ -370,6 +370,8 @@ export class PDFViewerBaseElement extends PolymerElement {
     const visiblePage = this.viewport_.getMostVisiblePage();
     const visiblePageDimensions = this.viewport_.getPageScreenRect(visiblePage);
     const size = this.viewport_.size;
+    this.paramsParser.setViewportDimensions(size);
+
     this.sendScriptingMessage({
       type: 'viewport',
       pageX: visiblePageDimensions.x,
@@ -426,6 +428,7 @@ export class PDFViewerBaseElement extends PolymerElement {
     this.documentDimensions = documentDimensions;
     this.isUserInitiatedEvent = false;
     this.viewport_.setDocumentDimensions(this.documentDimensions);
+    this.paramsParser.setViewportDimensions(this.viewport_.size);
     this.isUserInitiatedEvent = true;
   }
 

chrome/browser/resources/pdf/viewport.js

@@ -32,7 +32,7 @@ export let LayoutOptions;
 export let PartialPoint;
 
 /** @typedef {{width: number, height: number}} */
-let Size;
+export let Size;
 
 /** @typedef {{x: number, y: number, width: number, height: number}} */
 let ViewportRect;

chrome/test/data/pdf/params_parser_test.js

@@ -13,6 +13,10 @@ const tests = [
    */
   function testParamsParser() {
     const paramsParser = new OpenPdfParamsParser(function(destination) {
+      // Set the dummy viewport dimensions for calculating the zoom level for
+      // view destination with 'FitR' type.
+      paramsParser.setViewportDimensions({width: 300, height: 500});
+
       if (destination === 'RU') {
         return Promise.resolve(
             {messageId: 'getNamedDestination_1', pageNumber: 26});
@@ -40,9 +44,27 @@ const tests = [
           namedDestinationView: 'XYZ,111,null,1.7',
           pageNumber: 13
         });
+      } else if (destination === 'DestWithFitR') {
+        return Promise.resolve({
+          messageId: 'getNamedDestination_7',
+          namedDestinationView: 'FitR,20,100,120,300',
+          pageNumber: 0
+        });
+      } else if (destination === 'DestWithFitRReversedCoordinates') {
+        return Promise.resolve({
+          messageId: 'getNamedDestination_8',
+          namedDestinationView: 'FitR,120,300,20,100',
+          pageNumber: 0
+        });
+      } else if (destination === 'DestWithFitRWithNull') {
+        return Promise.resolve({
+          messageId: 'getNamedDestination_9',
+          namedDestinationView: 'FitR,null,100,100,300',
+          pageNumber: 0
+        });
       } else {
         return Promise.resolve(
-            {messageId: 'getNamedDestination_7', pageNumber: -1});
+            {messageId: 'getNamedDestination_10', pageNumber: -1});
       }
     });
 
@@ -142,6 +164,38 @@ const tests = [
           chrome.test.assertEq(undefined, params.viewPosition);
         });
 
+    // Checking #nameddest=name with a nameddest that specifies the view fit
+    // type is "FitR" with multiple valid parameters.
+    paramsParser.getViewportFromUrlParams(
+        `${url}#nameddest=DestWithFitR`, function(params) {
+          chrome.test.assertEq(0, params.page);
+          chrome.test.assertEq(2.5, params.zoom);
+          chrome.test.assertEq(20, params.position.x);
+          chrome.test.assertEq(100, params.position.y);
+          chrome.test.assertEq(undefined, params.viewPosition);
+        });
+
+    // Checking #nameddest=name with a nameddest that specifies the view fit
+    // type is "FitR" with multiple valid parameters.
+    paramsParser.getViewportFromUrlParams(
+        `${url}#nameddest=DestWithFitRReversedCoordinates`, function(params) {
+          chrome.test.assertEq(0, params.page);
+          chrome.test.assertEq(2.5, params.zoom);
+          chrome.test.assertEq(20, params.position.x);
+          chrome.test.assertEq(100, params.position.y);
+          chrome.test.assertEq(undefined, params.viewPosition);
+        });
+
+    // Checking #nameddest=name with a nameddest that specifies the view fit
+    // type is "FitR" with one NULL parameters.
+    paramsParser.getViewportFromUrlParams(
+        `${url}#nameddest=DestWithFitRWithNull`, function(params) {
+          chrome.test.assertEq(0, params.page);
+          chrome.test.assertEq(undefined, params.zoom);
+          chrome.test.assertEq(undefined, params.position);
+          chrome.test.assertEq(undefined, params.viewPosition);
+        });
+
     // Checking #view=Fit.
     paramsParser.getViewportFromUrlParams(`${url}#view=Fit`, function(params) {
       chrome.test.assertEq(FittingType.FIT_TO_PAGE, params.view);
@@ -205,6 +259,20 @@ const tests = [
           chrome.test.assertEq(undefined, params.view);
           chrome.test.assertEq(undefined, params.viewPosition);
         });
+    // Checking #view=[wrong parameter].
+    paramsParser.getViewportFromUrlParams(`${url}#view=FitR`, function(params) {
+      chrome.test.assertEq(undefined, params.view);
+      chrome.test.assertEq(undefined, params.viewPosition);
+    });
+    // Checking #view=[wrong parameter],[position].
+    paramsParser.getViewportFromUrlParams(
+        `${url}#view=FitR,20,100,120,300`, function(params) {
+          chrome.test.assertEq(undefined, params.zoom);
+          chrome.test.assertEq(undefined, params.position);
+          chrome.test.assertEq(undefined, params.view);
+          chrome.test.assertEq(undefined, params.viewPosition);
+        });
+
 
     // Checking #toolbar=0 to disable the toolbar.
     chrome.test.assertFalse(paramsParser.shouldShowToolbar(`${url}#toolbar=0`));