| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| /** |
| * @typedef {{ |
| * width: number, |
| * height: number, |
| * layoutOptions: (!LayoutOptions|undefined), |
| * pageDimensions: Array<ViewportRect>, |
| * }} |
| */ |
| let DocumentDimensions; |
| |
| /** @typedef {{defaultPageOrientation: number}} */ |
| let LayoutOptions; |
| |
| /** @typedef {{x: number, y: number}} */ |
| let Point; |
| |
| /** @typedef {{x: (number|undefined), y: (number|undefined)}} */ |
| let PartialPoint; |
| |
| /** @typedef {{width: number, height: number}} */ |
| let Size; |
| |
| /** @typedef {{x: number, y: number, width: number, height: number}} */ |
| let ViewportRect; |
| |
| /** |
| * Clamps the zoom factor (or page scale factor) to be within the limits. |
| * @param {number} factor The zoom/scale factor. |
| * @return {number} The factor clamped within the limits. |
| */ |
| function clampZoom(factor) { |
| return Math.max( |
| Viewport.ZOOM_FACTOR_RANGE.min, |
| Math.min(factor, Viewport.ZOOM_FACTOR_RANGE.max)); |
| } |
| |
| /** |
| * @param {!ViewportRect} rect1 |
| * @param {!ViewportRect} rect2 |
| * @return {number} The area of the intersection of the rects |
| */ |
| function getIntersectionArea(rect1, rect2) { |
| const left = Math.max(rect1.x, rect2.x); |
| const top = Math.max(rect1.y, rect2.y); |
| const right = Math.min(rect1.x + rect1.width, rect2.x + rect2.width); |
| const bottom = Math.min(rect1.y + rect1.height, rect2.y + rect2.height); |
| |
| if (left >= right || top >= bottom) { |
| return 0; |
| } |
| |
| return (right - left) * (bottom - top); |
| } |
| |
| /** |
| * @param {!Point} p1 |
| * @param {!Point} p2 |
| * @return {!Point} The vector between the two points. |
| */ |
| function vectorDelta(p1, p2) { |
| return {x: p2.x - p1.x, y: p2.y - p1.y}; |
| } |
| |
| /** |
| * @param {!Point} coordinateInFrame |
| * @return {!Point} Coordinate converted to plugin coordinates. |
| */ |
| function frameToPluginCoordinate(coordinateInFrame) { |
| const container = $('plugin'); |
| return { |
| x: coordinateInFrame.x - container.getBoundingClientRect().left, |
| y: coordinateInFrame.y - container.getBoundingClientRect().top |
| }; |
| } |
| |
| class Viewport { |
| /** |
| * @param {!Window} window |
| * @param {!HTMLDivElement} sizer The element which represents the size of the |
| * document in the viewport |
| * @param {number} scrollbarWidth The width of scrollbars on the page |
| * @param {number} defaultZoom The default zoom level. |
| * @param {number} topToolbarHeight The number of pixels that should initially |
| * be left blank above the document for the toolbar. |
| */ |
| constructor(window, sizer, scrollbarWidth, defaultZoom, topToolbarHeight) { |
| /** @private {!Window} */ |
| this.window_ = window; |
| |
| /** @private {!HTMLDivElement} */ |
| this.sizer_ = sizer; |
| |
| /** @private {number} */ |
| this.scrollbarWidth_ = scrollbarWidth; |
| |
| /** @private {number} */ |
| this.defaultZoom_ = defaultZoom; |
| |
| /** @private {number} */ |
| this.topToolbarHeight_ = topToolbarHeight; |
| |
| /** @private {function():void} */ |
| this.viewportChangedCallback_ = function() {}; |
| |
| /** @private {function():void} */ |
| this.beforeZoomCallback_ = function() {}; |
| |
| /** @private {function():void} */ |
| this.afterZoomCallback_ = function() {}; |
| |
| /** @private {function(boolean):void} */ |
| this.userInitiatedCallback_ = function() {}; |
| |
| /** @private {boolean} */ |
| this.allowedToChangeZoom_ = false; |
| |
| /** @private {number} */ |
| this.internalZoom_ = 1; |
| |
| /** @private {?ZoomManager} */ |
| this.zoomManager_ = null; |
| |
| /** @private {?DocumentDimensions} */ |
| this.documentDimensions_ = null; |
| |
| /** @private {Array<ViewportRect>} */ |
| this.pageDimensions_ = []; |
| |
| /** @private {!FittingType} */ |
| this.fittingType_ = FittingType.NONE; |
| |
| /** |
| * |twoUpView_| should be in sync with |two_up_view_| in PDFiumEngine. |
| * @private {boolean} |
| */ |
| this.twoUpView_ = false; |
| |
| /** @private {number} */ |
| this.prevScale_ = 1; |
| |
| /** @private {!Viewport.PinchPhase} */ |
| this.pinchPhase_ = Viewport.PinchPhase.PINCH_NONE; |
| |
| /** @private {?Point} */ |
| this.pinchPanVector_ = null; |
| |
| /** @private {?Point} */ |
| this.pinchCenter_ = null; |
| |
| /** @private {?Point} */ |
| this.firstPinchCenterInFrame_ = null; |
| |
| /** @private {number} */ |
| this.rotations_ = 0; |
| |
| /** @private {?Point} */ |
| this.oldCenterInContent_ = null; |
| |
| /** @private {boolean} */ |
| this.keepContentCentered_ = false; |
| |
| /** @private {!EventTracker} */ |
| this.tracker_ = new EventTracker(); |
| |
| // Set to a default zoom manager - used in tests. |
| this.setZoomManager(new InactiveZoomManager(this.getZoom.bind(this), 1)); |
| |
| window.addEventListener('scroll', this.updateViewport_.bind(this)); |
| window.addEventListener('resize', this.resizeWrapper_.bind(this)); |
| } |
| |
| /** @param {function():void} viewportChangedCallback */ |
| setViewportChangedCallback(viewportChangedCallback) { |
| this.viewportChangedCallback_ = viewportChangedCallback; |
| } |
| |
| /** @param {function():void} beforeZoomCallback */ |
| setBeforeZoomCallback(beforeZoomCallback) { |
| this.beforeZoomCallback_ = beforeZoomCallback; |
| } |
| |
| /** @param {function():void} afterZoomCallback */ |
| setAfterZoomCallback(afterZoomCallback) { |
| this.afterZoomCallback_ = afterZoomCallback; |
| } |
| |
| /** @param {function(boolean):void} userInitiatedCallback */ |
| setUserInitiatedCallback(userInitiatedCallback) { |
| this.userInitiatedCallback_ = userInitiatedCallback; |
| } |
| |
| /** |
| * @param {number} n The number of clockwise 90-degree rotations to increment |
| * by. |
| */ |
| rotateClockwise(n) { |
| this.rotations_ = (this.rotations_ + n) % 4; |
| } |
| |
| /** |
| * @return {number} The number of clockwise 90-degree rotations that have been |
| * applied. |
| */ |
| getClockwiseRotations() { |
| return this.rotations_; |
| } |
| |
| /** @param {boolean} twoUpView The new two up view state to set. */ |
| setTwoUpView(twoUpView) { |
| this.twoUpView_ = twoUpView; |
| } |
| |
| /** |
| * Converts a page position (e.g. the location of a bookmark) to a screen |
| * position. |
| * @param {number} page |
| * @param {!Point} point The position on `page`. |
| * @return {!Point} The screen position. |
| */ |
| convertPageToScreen(page, point) { |
| const dimensions = this.getPageInsetDimensions(page); |
| |
| // width & height are already rotated. |
| const height = dimensions.height; |
| const width = dimensions.width; |
| |
| const matrix = new DOMMatrix(); |
| |
| const rotation = this.rotations_ * 90; |
| // Set origin for rotation. |
| if (rotation == 90) { |
| matrix.translateSelf(width, 0); |
| } else if (rotation == 180) { |
| matrix.translateSelf(width, height); |
| } else if (rotation == 270) { |
| matrix.translateSelf(0, height); |
| } |
| matrix.rotateSelf(0, 0, rotation); |
| |
| // Invert Y position with respect to height as page coordinates are |
| // measured from the bottom left. |
| matrix.translateSelf(0, height); |
| matrix.scaleSelf(1, -1); |
| |
| const pointsToPixels = 96 / 72; |
| const result = matrix.transformPoint({ |
| x: point.x * pointsToPixels, |
| y: point.y * pointsToPixels, |
| }); |
| return { |
| x: result.x + Viewport.PAGE_SHADOW.left, |
| y: result.y + Viewport.PAGE_SHADOW.top, |
| }; |
| } |
| |
| |
| /** |
| * Returns the zoomed and rounded document dimensions for the given zoom. |
| * Rounding is necessary when interacting with the renderer which tends to |
| * operate in integral values (for example for determining if scrollbars |
| * should be shown). |
| * @param {number} zoom The zoom to use to compute the scaled dimensions. |
| * @return {?Size} Scaled 'width' and 'height' of the document. |
| * @private |
| */ |
| getZoomedDocumentDimensions_(zoom) { |
| if (!this.documentDimensions_) { |
| return null; |
| } |
| return { |
| width: Math.round(this.documentDimensions_.width * zoom), |
| height: Math.round(this.documentDimensions_.height * zoom) |
| }; |
| } |
| |
| /** @return {!Size} A dictionary with the 'width'/'height' of the document. */ |
| getDocumentDimensions() { |
| return { |
| width: this.documentDimensions_.width, |
| height: this.documentDimensions_.height |
| }; |
| } |
| |
| /** |
| * @return {!LayoutOptions|undefined} A dictionary carrying layout options |
| * from the plugin. |
| */ |
| getLayoutOptions() { |
| return this.documentDimensions_ ? this.documentDimensions_.layoutOptions : |
| undefined; |
| } |
| |
| /** |
| * @return {!ViewportRect} ViewportRect for the viewport given current zoom. |
| * @private |
| */ |
| getViewportRect_() { |
| const zoom = this.getZoom(); |
| return { |
| x: this.position.x / zoom, |
| y: this.position.y / zoom, |
| width: this.size.width / zoom, |
| height: this.size.height / zoom |
| }; |
| } |
| |
| /** |
| * @param {number} zoom Zoom to compute scrollbars for |
| * @return {{horizontal: boolean, vertical: boolean}} Whether horizontal or |
| * vertical scrollbars are needed. |
| * @private |
| */ |
| documentNeedsScrollbars_(zoom) { |
| const zoomedDimensions = this.getZoomedDocumentDimensions_(zoom); |
| if (!zoomedDimensions) { |
| return {horizontal: false, vertical: false}; |
| } |
| |
| // If scrollbars are required for one direction, expand the document in the |
| // other direction to take the width of the scrollbars into account when |
| // deciding whether the other direction needs scrollbars. |
| if (zoomedDimensions.width > this.window_.innerWidth) { |
| zoomedDimensions.height += this.scrollbarWidth_; |
| } else if (zoomedDimensions.height > this.window_.innerHeight) { |
| zoomedDimensions.width += this.scrollbarWidth_; |
| } |
| return { |
| horizontal: zoomedDimensions.width > this.window_.innerWidth, |
| vertical: zoomedDimensions.height + this.topToolbarHeight_ > |
| this.window_.innerHeight |
| }; |
| } |
| |
| /** |
| * @return {!{horizontal: boolean, vertical: boolean}} Whether horizontal and |
| * vertical scrollbars are needed. |
| */ |
| documentHasScrollbars() { |
| return this.documentNeedsScrollbars_(this.getZoom()); |
| } |
| |
| /** |
| * Helper function called when the zoomed document size changes. Updates the |
| * sizer's width and height. |
| * @private |
| */ |
| contentSizeChanged_() { |
| const zoomedDimensions = this.getZoomedDocumentDimensions_(this.getZoom()); |
| if (zoomedDimensions) { |
| this.sizer_.style.width = zoomedDimensions.width + 'px'; |
| this.sizer_.style.height = |
| zoomedDimensions.height + this.topToolbarHeight_ + 'px'; |
| } |
| } |
| |
| /** |
| * Called when the viewport should be updated. |
| * @private |
| */ |
| updateViewport_() { |
| this.viewportChangedCallback_(); |
| } |
| |
| /** |
| * Called when the browser window size changes. |
| * @private |
| */ |
| resizeWrapper_() { |
| this.userInitiatedCallback_(false); |
| this.resize_(); |
| this.userInitiatedCallback_(true); |
| } |
| |
| /** |
| * Called when the viewport size changes. |
| * @private |
| */ |
| resize_() { |
| if (this.fittingType_ == FittingType.FIT_TO_PAGE) { |
| this.fitToPageInternal_(false); |
| } else if (this.fittingType_ == FittingType.FIT_TO_WIDTH) { |
| this.fitToWidth(); |
| } else if (this.fittingType_ == FittingType.FIT_TO_HEIGHT) { |
| this.fitToHeightInternal_(false); |
| } else if (this.internalZoom_ == 0) { |
| this.fitToNone(); |
| } else { |
| this.updateViewport_(); |
| } |
| } |
| |
| /** @return {!Point} The scroll position of the viewport. */ |
| get position() { |
| return { |
| x: this.window_.pageXOffset, |
| y: this.window_.pageYOffset - this.topToolbarHeight_ |
| }; |
| } |
| |
| /** |
| * Scroll the viewport to the specified position. |
| * @param {!Point} position The position to scroll to. |
| */ |
| set position(position) { |
| this.window_.scrollTo(position.x, position.y + this.topToolbarHeight_); |
| } |
| |
| /** @return {!Size} the size of the viewport excluding scrollbars. */ |
| get size() { |
| const needsScrollbars = this.documentNeedsScrollbars_(this.getZoom()); |
| const scrollbarWidth = needsScrollbars.vertical ? this.scrollbarWidth_ : 0; |
| const scrollbarHeight = |
| needsScrollbars.horizontal ? this.scrollbarWidth_ : 0; |
| return { |
| width: this.window_.innerWidth - scrollbarWidth, |
| height: this.window_.innerHeight - scrollbarHeight |
| }; |
| } |
| |
| /** @return {number} The current zoom. */ |
| getZoom() { |
| return this.zoomManager_.applyBrowserZoom(this.internalZoom_); |
| } |
| |
| /** @param {!ZoomManager} manager */ |
| setZoomManager(manager) { |
| this.resetTracker(); |
| this.zoomManager_ = manager; |
| this.tracker_.add( |
| this.zoomManager_.getEventTarget(), 'set-zoom', |
| e => this.setZoom(e.detail)); |
| this.tracker_.add( |
| this.zoomManager_.getEventTarget(), 'update-zoom-from-browser', |
| this.updateZoomFromBrowserChange_.bind(this)); |
| } |
| |
| /** |
| * @return {!Viewport.PinchPhase} The phase of the current pinch gesture for |
| * the viewport. |
| */ |
| get pinchPhase() { |
| return this.pinchPhase_; |
| } |
| |
| /** |
| * @return {?Point} The panning caused by the current pinch gesture (as |
| * the deltas of the x and y coordinates). |
| */ |
| get pinchPanVector() { |
| return this.pinchPanVector_; |
| } |
| |
| /** |
| * @return {?Point} The coordinates of the center of the current pinch |
| * gesture. |
| */ |
| get pinchCenter() { |
| return this.pinchCenter_; |
| } |
| |
| /** |
| * Used to wrap a function that might perform zooming on the viewport. This is |
| * required so that we can notify the plugin that zooming is in progress |
| * so that while zooming is taking place it can stop reacting to scroll events |
| * from the viewport. This is to avoid flickering. |
| * @param {function():void} f Function to wrap |
| * @private |
| */ |
| mightZoom_(f) { |
| this.beforeZoomCallback_(); |
| this.allowedToChangeZoom_ = true; |
| f(); |
| this.allowedToChangeZoom_ = false; |
| this.afterZoomCallback_(); |
| this.zoomManager_.onPdfZoomChange(); |
| } |
| |
| /** |
| * @param {number} newZoom The zoom level to set. |
| * @private |
| */ |
| setZoomInternal_(newZoom) { |
| assert( |
| this.allowedToChangeZoom_, |
| 'Called Viewport.setZoomInternal_ without calling ' + |
| 'Viewport.mightZoom_.'); |
| // Record the scroll position (relative to the top-left of the window). |
| let zoom = this.getZoom(); |
| const currentScrollPos = { |
| x: this.position.x / zoom, |
| y: this.position.y / zoom |
| }; |
| |
| this.internalZoom_ = newZoom; |
| this.contentSizeChanged_(); |
| // Scroll to the scaled scroll position. |
| zoom = this.getZoom(); |
| this.position = { |
| x: currentScrollPos.x * zoom, |
| y: currentScrollPos.y * zoom |
| }; |
| } |
| |
| /** |
| * Sets the zoom of the viewport. |
| * Same as setZoomInternal_ but for pinch zoom we have some more operations. |
| * @param {number} scaleDelta The zoom delta. |
| * @param {!Point} center The pinch center in content coordinates. |
| * @private |
| */ |
| setPinchZoomInternal_(scaleDelta, center) { |
| assert( |
| this.allowedToChangeZoom_, |
| 'Called Viewport.setPinchZoomInternal_ without calling ' + |
| 'Viewport.mightZoom_.'); |
| this.internalZoom_ = clampZoom(this.internalZoom_ * scaleDelta); |
| |
| const newCenterInContent = this.frameToContent_(center); |
| const delta = { |
| x: (newCenterInContent.x - this.oldCenterInContent_.x), |
| y: (newCenterInContent.y - this.oldCenterInContent_.y) |
| }; |
| |
| // Record the scroll position (relative to the pinch center). |
| const zoom = this.getZoom(); |
| const currentScrollPos = { |
| x: this.position.x - delta.x * zoom, |
| y: this.position.y - delta.y * zoom |
| }; |
| |
| this.contentSizeChanged_(); |
| // Scroll to the scaled scroll position. |
| this.position = {x: currentScrollPos.x, y: currentScrollPos.y}; |
| } |
| |
| /** |
| * Converts a point from frame to content coordinates. |
| * @param {!Point} framePoint The frame coordinates. |
| * @return {!Point} The content coordinates. |
| * @private |
| */ |
| frameToContent_(framePoint) { |
| // TODO(mcnee) Add a helper Point class to avoid duplicating operations |
| // on plain {x,y} objects. |
| const zoom = this.getZoom(); |
| return { |
| x: (framePoint.x + this.position.x) / zoom, |
| y: (framePoint.y + this.position.y) / zoom |
| }; |
| } |
| |
| /** |
| * @param {number} newZoom The zoom level to zoom to. |
| */ |
| setZoom(newZoom) { |
| this.fittingType_ = FittingType.NONE; |
| this.mightZoom_(() => { |
| this.setZoomInternal_(clampZoom(newZoom)); |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** |
| * @param {!CustomEvent<number>} e Event containing the old browser zoom. |
| * @private |
| */ |
| updateZoomFromBrowserChange_(e) { |
| const oldBrowserZoom = e.detail; |
| this.mightZoom_(() => { |
| // Record the scroll position (relative to the top-left of the window). |
| const oldZoom = oldBrowserZoom * this.internalZoom_; |
| const currentScrollPos = { |
| x: this.position.x / oldZoom, |
| y: this.position.y / oldZoom |
| }; |
| this.contentSizeChanged_(); |
| const newZoom = this.getZoom(); |
| // Scroll to the scaled scroll position. |
| this.position = { |
| x: currentScrollPos.x * newZoom, |
| y: currentScrollPos.y * newZoom |
| }; |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** @return {number} The width of scrollbars in the viewport in pixels. */ |
| get scrollbarWidth() { |
| return this.scrollbarWidth_; |
| } |
| |
| /** @return {FittingType} The fitting type the viewport is currently in. */ |
| get fittingType() { |
| return this.fittingType_; |
| } |
| |
| /** |
| * Get the page at a given y position. If there are multiple pages |
| * overlapping the given y-coordinate, return the page with the smallest |
| * index. |
| * @param {number} y The y-coordinate to get the page at. |
| * @return {number} The index of a page overlapping the given y-coordinate. |
| * @private |
| */ |
| getPageAtY_(y) { |
| let min = 0; |
| let max = this.pageDimensions_.length - 1; |
| while (max >= min) { |
| const page = Math.floor(min + ((max - min) / 2)); |
| // There might be a gap between the pages, in which case use the bottom |
| // of the previous page as the top for finding the page. |
| let top = 0; |
| if (page > 0) { |
| top = this.pageDimensions_[page - 1].y + |
| this.pageDimensions_[page - 1].height; |
| } |
| const bottom = |
| this.pageDimensions_[page].y + this.pageDimensions_[page].height; |
| |
| if (top <= y && y <= bottom) { |
| return page; |
| } |
| |
| if (top > y) { |
| max = page - 1; |
| } else { |
| min = page + 1; |
| } |
| } |
| return 0; |
| } |
| |
| /** |
| * Return the last page visible in the viewport. Returns the last index of the |
| * document if the viewport is below the document. |
| * @param {!ViewportRect} viewportRect |
| * @return {number} The highest index of the pages visible in the viewport. |
| * @private |
| */ |
| getLastPageInViewport_(viewportRect) { |
| const pageAtY = this.getPageAtY_(viewportRect.y + viewportRect.height); |
| |
| if (!this.twoUpView_ || pageAtY % 2 == 1 || |
| pageAtY + 1 >= this.pageDimensions_.length) { |
| return pageAtY; |
| } |
| |
| const nextPage = this.pageDimensions_[pageAtY + 1]; |
| return getIntersectionArea(viewportRect, nextPage) > 0 ? pageAtY + 1 : |
| pageAtY; |
| } |
| |
| /** |
| * @param {!Point} point |
| * @return {boolean} Whether |point| (in screen coordinates) is inside a page |
| */ |
| isPointInsidePage(point) { |
| const zoom = this.getZoom(); |
| const size = this.size; |
| const position = this.position; |
| const page = this.getPageAtY_((position.y + point.y) / zoom); |
| const pageWidth = this.pageDimensions_[page].width * zoom; |
| const documentWidth = this.getDocumentDimensions().width * zoom; |
| |
| const outerWidth = Math.max(size.width, documentWidth); |
| |
| if (pageWidth >= outerWidth) { |
| return true; |
| } |
| |
| const x = point.x + position.x; |
| |
| const minX = (outerWidth - pageWidth) / 2; |
| const maxX = outerWidth - minX; |
| return x >= minX && x <= maxX; |
| } |
| |
| /** |
| * @return {number} The index of the page with the greatest proportion of its |
| * area in the current viewport. |
| */ |
| getMostVisiblePage() { |
| const viewportRect = this.getViewportRect_(); |
| |
| const firstVisiblePage = this.getPageAtY_(viewportRect.y); |
| const lastPossibleVisiblePage = this.getLastPageInViewport_(viewportRect); |
| if (firstVisiblePage === lastPossibleVisiblePage) { |
| return firstVisiblePage; |
| } |
| |
| let mostVisiblePage = firstVisiblePage; |
| let largestIntersection = 0; |
| |
| for (let i = firstVisiblePage; i < lastPossibleVisiblePage + 1; i++) { |
| const pageArea = |
| this.pageDimensions_[i].width * this.pageDimensions_[i].height; |
| |
| // TODO(thestig): check whether we can remove this check. |
| if (pageArea <= 0) { |
| continue; |
| } |
| |
| const pageIntersectionArea = |
| getIntersectionArea(this.pageDimensions_[i], viewportRect) / pageArea; |
| |
| if (pageIntersectionArea > largestIntersection) { |
| mostVisiblePage = i; |
| largestIntersection = pageIntersectionArea; |
| } |
| } |
| |
| return mostVisiblePage; |
| } |
| |
| /** |
| * Compute the zoom level for fit-to-page, fit-to-width or fit-to-height. |
| * At least one of {fitWidth, fitHeight} must be true. |
| * @param {!Size} pageDimensions The dimensions of a given page in px. |
| * @param {boolean} fitWidth Whether the whole width of the page needs to be |
| * in the viewport. |
| * @param {boolean} fitHeight Whether the whole height of the page needs to be |
| * in the viewport. |
| * @return {number} The internal zoom to set |
| * @private |
| */ |
| computeFittingZoom_(pageDimensions, fitWidth, fitHeight) { |
| assert( |
| fitWidth || fitHeight, |
| 'Invalid parameters. At least one of fitWidth and fitHeight must be ' + |
| 'true.'); |
| |
| // First compute the zoom without scrollbars. |
| let zoom = this.computeFittingZoomGivenDimensions_( |
| fitWidth, fitHeight, this.window_.innerWidth, this.window_.innerHeight, |
| pageDimensions.width, pageDimensions.height); |
| |
| // Check if there needs to be any scrollbars. |
| const needsScrollbars = this.documentNeedsScrollbars_(zoom); |
| |
| // If the document fits, just return the zoom. |
| if (!needsScrollbars.horizontal && !needsScrollbars.vertical) { |
| return zoom; |
| } |
| |
| const zoomedDimensions = this.getZoomedDocumentDimensions_(zoom); |
| |
| // Check if adding a scrollbar will result in needing the other scrollbar. |
| const scrollbarWidth = this.scrollbarWidth_; |
| if (needsScrollbars.horizontal && |
| zoomedDimensions.height > this.window_.innerHeight - scrollbarWidth) { |
| needsScrollbars.vertical = true; |
| } |
| if (needsScrollbars.vertical && |
| zoomedDimensions.width > this.window_.innerWidth - scrollbarWidth) { |
| needsScrollbars.horizontal = true; |
| } |
| |
| // Compute available window space. |
| const windowWithScrollbars = { |
| width: this.window_.innerWidth, |
| height: this.window_.innerHeight |
| }; |
| if (needsScrollbars.horizontal) { |
| windowWithScrollbars.height -= scrollbarWidth; |
| } |
| if (needsScrollbars.vertical) { |
| windowWithScrollbars.width -= scrollbarWidth; |
| } |
| |
| // Recompute the zoom. |
| zoom = this.computeFittingZoomGivenDimensions_( |
| fitWidth, fitHeight, windowWithScrollbars.width, |
| windowWithScrollbars.height, pageDimensions.width, |
| pageDimensions.height); |
| |
| return this.zoomManager_.internalZoomComponent(zoom); |
| } |
| |
| /** |
| * Compute a zoom level given the dimensions to fit and the actual numbers |
| * in those dimensions. |
| * @param {boolean} fitWidth Whether to constrain the page width to the |
| * window. |
| * @param {boolean} fitHeight Whether to constrain the page height to the |
| * window. |
| * @param {number} windowWidth Width of the window in px. |
| * @param {number} windowHeight Height of the window in px. |
| * @param {number} pageWidth Width of the page in px. |
| * @param {number} pageHeight Height of the page in px. |
| * @return {number} The internal zoom to set |
| * @private |
| */ |
| computeFittingZoomGivenDimensions_( |
| fitWidth, fitHeight, windowWidth, windowHeight, pageWidth, pageHeight) { |
| // Assumes at least one of {fitWidth, fitHeight} is set. |
| let zoomWidth; |
| let zoomHeight; |
| |
| if (fitWidth) { |
| zoomWidth = windowWidth / pageWidth; |
| } |
| |
| if (fitHeight) { |
| zoomHeight = windowHeight / pageHeight; |
| } |
| |
| let zoom; |
| if (!fitWidth && fitHeight) { |
| zoom = zoomHeight; |
| } else if (fitWidth && !fitHeight) { |
| zoom = zoomWidth; |
| } else { |
| // Assume fitWidth && fitHeight |
| zoom = Math.min(zoomWidth, zoomHeight); |
| } |
| |
| return Math.max(zoom, 0); |
| } |
| |
| /** Zoom the viewport so that the page width consumes the entire viewport. */ |
| fitToWidth() { |
| this.mightZoom_(() => { |
| this.fittingType_ = FittingType.FIT_TO_WIDTH; |
| if (!this.documentDimensions_) { |
| return; |
| } |
| // When computing fit-to-width, the maximum width of a page in the |
| // document is used, which is equal to the size of the document width. |
| this.setZoomInternal_( |
| this.computeFittingZoom_(this.documentDimensions_, true, false)); |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** |
| * Zoom the viewport so that the page height consumes the entire viewport. |
| * @param {boolean} scrollToTopOfPage Set to true if the viewport should be |
| * scrolled to the top of the current page. Set to false if the viewport |
| * should remain at the current scroll position. |
| * @private |
| */ |
| fitToHeightInternal_(scrollToTopOfPage) { |
| this.mightZoom_(() => { |
| this.fittingType_ = FittingType.FIT_TO_HEIGHT; |
| if (!this.documentDimensions_) { |
| return; |
| } |
| const page = this.getMostVisiblePage(); |
| // When computing fit-to-height, the maximum height of the current page |
| // is used. |
| const dimensions = { |
| width: 0, |
| height: this.pageDimensions_[page].height, |
| }; |
| this.setZoomInternal_(this.computeFittingZoom_(dimensions, false, true)); |
| if (scrollToTopOfPage) { |
| this.position = { |
| x: 0, |
| y: this.pageDimensions_[page].y * this.getZoom() |
| }; |
| } |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** Zoom the viewport so that the page height consumes the entire viewport. */ |
| fitToHeight() { |
| this.fitToHeightInternal_(true); |
| } |
| |
| /** |
| * Zoom the viewport so that a page consumes as much as possible of the it. |
| * @param {boolean} scrollToTopOfPage Whether the viewport should be scrolled |
| * to the top of the current page. If false, the viewport will remain at |
| * the current scroll position. |
| * @private |
| */ |
| fitToPageInternal_(scrollToTopOfPage) { |
| this.mightZoom_(() => { |
| this.fittingType_ = FittingType.FIT_TO_PAGE; |
| if (!this.documentDimensions_) { |
| return; |
| } |
| const page = this.getMostVisiblePage(); |
| // Fit to the current page's height and the widest page's width. |
| const dimensions = { |
| width: this.documentDimensions_.width, |
| height: this.pageDimensions_[page].height, |
| }; |
| this.setZoomInternal_(this.computeFittingZoom_(dimensions, true, true)); |
| if (scrollToTopOfPage) { |
| this.position = { |
| x: 0, |
| y: this.pageDimensions_[page].y * this.getZoom() |
| }; |
| } |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** |
| * Zoom the viewport so that a page consumes the entire viewport. Also scrolls |
| * the viewport to the top of the current page. |
| */ |
| fitToPage() { |
| this.fitToPageInternal_(true); |
| } |
| |
| /** Zoom the viewport to the default zoom. */ |
| fitToNone() { |
| this.mightZoom_(() => { |
| this.fittingType_ = FittingType.NONE; |
| if (!this.documentDimensions_) { |
| return; |
| } |
| this.setZoomInternal_(Math.min( |
| this.defaultZoom_, |
| this.computeFittingZoom_(this.documentDimensions_, true, false))); |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** Zoom out to the next predefined zoom level. */ |
| zoomOut() { |
| this.mightZoom_(() => { |
| this.fittingType_ = FittingType.NONE; |
| let nextZoom = Viewport.ZOOM_FACTORS[0]; |
| for (let i = 0; i < Viewport.ZOOM_FACTORS.length; i++) { |
| if (Viewport.ZOOM_FACTORS[i] < this.internalZoom_) { |
| nextZoom = Viewport.ZOOM_FACTORS[i]; |
| } |
| } |
| this.setZoomInternal_(nextZoom); |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** Zoom in to the next predefined zoom level. */ |
| zoomIn() { |
| this.mightZoom_(() => { |
| this.fittingType_ = FittingType.NONE; |
| let nextZoom = Viewport.ZOOM_FACTORS[Viewport.ZOOM_FACTORS.length - 1]; |
| for (let i = Viewport.ZOOM_FACTORS.length - 1; i >= 0; i--) { |
| if (Viewport.ZOOM_FACTORS[i] > this.internalZoom_) { |
| nextZoom = Viewport.ZOOM_FACTORS[i]; |
| } |
| } |
| this.setZoomInternal_(nextZoom); |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** |
| * Pinch zoom event handler. |
| * @param {!Object} e The pinch event. |
| */ |
| pinchZoom(e) { |
| this.mightZoom_(() => { |
| this.pinchPhase_ = e.direction == 'out' ? |
| Viewport.PinchPhase.PINCH_UPDATE_ZOOM_OUT : |
| Viewport.PinchPhase.PINCH_UPDATE_ZOOM_IN; |
| |
| const scaleDelta = e.startScaleRatio / this.prevScale_; |
| if (this.firstPinchCenterInFrame_ != null) { |
| this.pinchPanVector_ = |
| vectorDelta(e.center, this.firstPinchCenterInFrame_); |
| } |
| |
| const needsScrollbars = |
| this.documentNeedsScrollbars_(this.zoomManager_.applyBrowserZoom( |
| clampZoom(this.internalZoom_ * scaleDelta))); |
| |
| this.pinchCenter_ = e.center; |
| |
| // If there's no horizontal scrolling, keep the content centered so the |
| // user can't zoom in on the non-content area. |
| // TODO(mcnee) Investigate other ways of scaling when we don't have |
| // horizontal scrolling. We want to keep the document centered, |
| // but this causes a potentially awkward transition when we start |
| // using the gesture center. |
| if (!needsScrollbars.horizontal) { |
| this.pinchCenter_ = { |
| x: this.window_.innerWidth / 2, |
| y: this.window_.innerHeight / 2 |
| }; |
| } else if (this.keepContentCentered_) { |
| this.oldCenterInContent_ = |
| this.frameToContent_(frameToPluginCoordinate(e.center)); |
| this.keepContentCentered_ = false; |
| } |
| |
| this.setPinchZoomInternal_(scaleDelta, frameToPluginCoordinate(e.center)); |
| this.updateViewport_(); |
| this.prevScale_ = e.startScaleRatio; |
| }); |
| } |
| |
| /** @param {!Object} e The pinch event. */ |
| pinchZoomStart(e) { |
| this.pinchPhase_ = Viewport.PinchPhase.PINCH_START; |
| this.prevScale_ = 1; |
| this.oldCenterInContent_ = |
| this.frameToContent_(frameToPluginCoordinate(e.center)); |
| |
| const needsScrollbars = this.documentNeedsScrollbars_(this.getZoom()); |
| this.keepContentCentered_ = !needsScrollbars.horizontal; |
| // We keep track of begining of the pinch. |
| // By doing so we will be able to compute the pan distance. |
| this.firstPinchCenterInFrame_ = e.center; |
| } |
| |
| /** @param {!Object} e The pinch event. */ |
| pinchZoomEnd(e) { |
| this.mightZoom_(() => { |
| this.pinchPhase_ = Viewport.PinchPhase.PINCH_END; |
| const scaleDelta = e.startScaleRatio / this.prevScale_; |
| this.pinchCenter_ = /** @type {!Point} */ (e.center); |
| |
| this.setPinchZoomInternal_(scaleDelta, frameToPluginCoordinate(e.center)); |
| this.updateViewport_(); |
| }); |
| |
| this.pinchPhase_ = Viewport.PinchPhase.PINCH_NONE; |
| this.pinchPanVector_ = null; |
| this.pinchCenter_ = null; |
| this.firstPinchCenterInFrame_ = null; |
| } |
| |
| /** |
| * Go to the next page. If the document is in two-up view, go to the left page |
| * of the next row. |
| */ |
| goToNextPage() { |
| const currentPage = this.getMostVisiblePage(); |
| const nextPageOffset = (this.twoUpView_ && currentPage % 2 == 0) ? 2 : 1; |
| this.goToPage(currentPage + nextPageOffset); |
| } |
| |
| /** |
| * Go to the previous page. If the document is in two-up view, go to the left |
| * page of the previous row. |
| */ |
| goToPreviousPage() { |
| const currentPage = this.getMostVisiblePage(); |
| let previousPageOffset = -1; |
| |
| if (this.twoUpView_) { |
| previousPageOffset = (currentPage % 2 == 0) ? -2 : -3; |
| } |
| |
| this.goToPage(currentPage + previousPageOffset); |
| } |
| |
| /** |
| * Go to the given page index. |
| * @param {number} page the index of the page to go to. zero-based. |
| */ |
| goToPage(page) { |
| this.goToPageAndXY(page, 0, 0); |
| } |
| |
| /** |
| * Go to the given y position in the given page index. |
| * @param {number} page the index of the page to go to. zero-based. |
| * @param {number} x the x position in the page to go to. |
| * @param {number} y the y position in the page to go to. |
| */ |
| goToPageAndXY(page, x, y) { |
| this.mightZoom_(() => { |
| if (this.pageDimensions_.length === 0) { |
| return; |
| } |
| if (page < 0) { |
| page = 0; |
| } |
| if (page >= this.pageDimensions_.length) { |
| page = this.pageDimensions_.length - 1; |
| } |
| const dimensions = this.pageDimensions_[page]; |
| let toolbarOffset = 0; |
| // Unless we're in fit to page or fit to height mode, scroll above the |
| // page by |this.topToolbarHeight_| so that the toolbar isn't covering it |
| // initially. |
| if (!this.isPagedMode()) { |
| toolbarOffset = this.topToolbarHeight_; |
| } |
| this.position = { |
| x: (dimensions.x + x) * this.getZoom(), |
| y: (dimensions.y + y) * this.getZoom() - toolbarOffset |
| }; |
| this.updateViewport_(); |
| }); |
| } |
| |
| /** |
| * @param {DocumentDimensions} documentDimensions The dimensions of the |
| * document |
| */ |
| setDocumentDimensions(documentDimensions) { |
| this.mightZoom_(() => { |
| const initialDimensions = !this.documentDimensions_; |
| this.documentDimensions_ = documentDimensions; |
| this.pageDimensions_ = this.documentDimensions_.pageDimensions; |
| if (initialDimensions) { |
| this.setZoomInternal_(Math.min( |
| this.defaultZoom_, |
| this.computeFittingZoom_(this.documentDimensions_, true, false))); |
| this.position = {x: 0, y: -this.topToolbarHeight_}; |
| } |
| this.contentSizeChanged_(); |
| this.resize_(); |
| }); |
| } |
| |
| /** |
| * @param {number} page |
| * @return {ViewportRect} The bounds for page `page` minus the shadows. |
| */ |
| getPageInsetDimensions(page) { |
| const pageDimensions = this.pageDimensions_[page]; |
| const shadow = Viewport.PAGE_SHADOW; |
| return { |
| x: pageDimensions.x + shadow.left, |
| y: pageDimensions.y + shadow.top, |
| width: pageDimensions.width - shadow.left - shadow.right, |
| height: pageDimensions.height - shadow.top - shadow.bottom, |
| }; |
| } |
| |
| /** |
| * Get the coordinates of the page contents (excluding the page shadow) |
| * relative to the screen. |
| * @param {number} page The index of the page to get the rect for. |
| * @return {!ViewportRect} A rect representing the page in screen coordinates. |
| */ |
| getPageScreenRect(page) { |
| if (!this.documentDimensions_) { |
| return {x: 0, y: 0, width: 0, height: 0}; |
| } |
| if (page >= this.pageDimensions_.length) { |
| page = this.pageDimensions_.length - 1; |
| } |
| |
| const pageDimensions = this.pageDimensions_[page]; |
| |
| // Compute the page dimensions minus the shadows. |
| const insetDimensions = this.getPageInsetDimensions(page); |
| |
| // Compute the x-coordinate of the page within the document. |
| // TODO(raymes): This should really be set when the PDF plugin passes the |
| // page coordinates, but it isn't yet. |
| const x = (this.documentDimensions_.width - pageDimensions.width) / 2 + |
| Viewport.PAGE_SHADOW.left; |
| // Compute the space on the left of the document if the document fits |
| // completely in the screen. |
| const zoom = this.getZoom(); |
| let spaceOnLeft = |
| (this.size.width - this.documentDimensions_.width * zoom) / 2; |
| spaceOnLeft = Math.max(spaceOnLeft, 0); |
| |
| return { |
| x: x * zoom + spaceOnLeft - this.window_.pageXOffset, |
| y: insetDimensions.y * zoom - this.window_.pageYOffset, |
| width: insetDimensions.width * zoom, |
| height: insetDimensions.height * zoom |
| }; |
| } |
| |
| /** |
| * Check if the current fitting type is a paged mode. |
| * In a paged mode, page up and page down scroll to the top of the |
| * previous/next page and part of the page is under the toolbar. |
| * @return {boolean} Whether the current fitting type is a paged mode. |
| */ |
| isPagedMode() { |
| return ( |
| this.fittingType_ == FittingType.FIT_TO_PAGE || |
| this.fittingType_ == FittingType.FIT_TO_HEIGHT); |
| } |
| |
| /** |
| * @param {!PartialPoint} point The position to which to scroll the viewport. |
| */ |
| scrollTo(point) { |
| let changed = false; |
| const newPosition = this.position; |
| if (point.x !== undefined && point.x != newPosition.x) { |
| newPosition.x = point.x; |
| changed = true; |
| } |
| if (point.y !== undefined && point.y != newPosition.y) { |
| newPosition.y = point.y; |
| changed = true; |
| } |
| |
| if (changed) { |
| this.position = newPosition; |
| } |
| } |
| |
| /** @param {!Point} delta The delta by which to scroll the viewport. */ |
| scrollBy(delta) { |
| const newPosition = this.position; |
| newPosition.x += delta.x; |
| newPosition.y += delta.y; |
| this.scrollTo(newPosition); |
| } |
| |
| /** Removes all events being tracked from the tracker. */ |
| resetTracker() { |
| if (this.tracker_) { |
| this.tracker_.removeAll(); |
| } |
| } |
| } |
| |
| /** |
| * Enumeration of pinch states. |
| * This should match PinchPhase enum in pdf/out_of_process_instance.h |
| * @enum {number} |
| */ |
| Viewport.PinchPhase = { |
| PINCH_NONE: 0, |
| PINCH_START: 1, |
| PINCH_UPDATE_ZOOM_OUT: 2, |
| PINCH_UPDATE_ZOOM_IN: 3, |
| PINCH_END: 4 |
| }; |
| |
| /** |
| * The increment to scroll a page by in pixels when up/down/left/right arrow |
| * keys are pressed. Usually we just let the browser handle scrolling on the |
| * window when these keys are pressed but in certain cases we need to simulate |
| * these events. |
| */ |
| Viewport.SCROLL_INCREMENT = 40; |
| |
| /** |
| * Predefined zoom factors to be used when zooming in/out. These are in |
| * ascending order. This should match the lists in |
| * components/zoom/page_zoom_constants.h and |
| * chrome/browser/resources/settings/appearance_page/appearance_page.js |
| */ |
| Viewport.ZOOM_FACTORS = [ |
| 0.25, 1 / 3, 0.5, 2 / 3, 0.75, 0.8, 0.9, 1, 1.1, 1.25, 1.5, 1.75, 2, 2.5, 3, |
| 4, 5 |
| ]; |
| |
| /** The minimum and maximum range to be used to clip zoom factor. */ |
| Viewport.ZOOM_FACTOR_RANGE = { |
| min: Viewport.ZOOM_FACTORS[0], |
| max: Viewport.ZOOM_FACTORS[Viewport.ZOOM_FACTORS.length - 1] |
| }; |
| |
| /** The width of the page shadow around pages in pixels. */ |
| Viewport.PAGE_SHADOW = { |
| top: 3, |
| bottom: 7, |
| left: 5, |
| right: 5 |
| }; |