/* * OpenSeadragon - DrawerBase * * Copyright (C) 2009 CodePlex Foundation * Copyright (C) 2010-2023 OpenSeadragon contributors * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * - Neither the name of CodePlex Foundation nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ (function( $ ){ /** * @class DrawerBase * @memberof OpenSeadragon * @classdesc Base class for Drawers that handle rendering of tiles for an {@link OpenSeadragon.Viewer}. * @param {Object} options - Options for this Drawer. * @param {OpenSeadragon.Viewer} options.viewer - The Viewer that owns this Drawer. * @param {OpenSeadragon.Viewport} options.viewport - Reference to Viewer viewport. * @param {Element} options.element - Parent element. */ $.DrawerBase = function( options ) { $.console.assert( options.viewer, "[Drawer] options.viewer is required" ); //backward compatibility for positional args while preferring more //idiomatic javascript options object as the only argument var args = arguments; if( !$.isPlainObject( options ) ){ options = { source: args[ 0 ], // Reference to Viewer tile source. viewport: args[ 1 ], // Reference to Viewer viewport. element: args[ 2 ] // Parent element. }; } $.console.assert( options.viewport, "[Drawer] options.viewport is required" ); $.console.assert( options.element, "[Drawer] options.element is required" ); if ( options.source ) { $.console.error( "[Drawer] options.source is no longer accepted; use TiledImage instead" ); } this.viewer = options.viewer; this.viewport = options.viewport; this.debugGridColor = typeof options.debugGridColor === 'string' ? [options.debugGridColor] : options.debugGridColor || $.DEFAULT_SETTINGS.debugGridColor; if (options.opacity) { $.console.error( "[Drawer] options.opacity is no longer accepted; set the opacity on the TiledImage instead" ); } this.useCanvas = $.supportsCanvas && ( this.viewer ? this.viewer.useCanvas : true ); /** * The parent element of this Drawer instance, passed in when the Drawer was created. * The parent of {@link OpenSeadragon.DrawerBase#canvas}. * @member {Element} container * @memberof OpenSeadragon.DrawerBase# */ this.container = $.getElement( options.element ); /** * A <canvas> element if the browser supports them, otherwise a <div> element. * Child element of {@link OpenSeadragon.DrawerBase#container}. * @member {Element} canvas * @memberof OpenSeadragon.DrawerBase# */ this.canvas = $.makeNeutralElement( this.useCanvas ? "canvas" : "div" ); /** * @member {Element} element * @memberof OpenSeadragon.DrawerBase# * @deprecated Alias for {@link OpenSeadragon.DrawerBase#container}. */ this.element = this.container; // TO DO: Does this need to be in DrawerBase, or only in Drawer implementations? // We force our container to ltr because our drawing math doesn't work in rtl. // This issue only affects our canvas renderer, but we do it always for consistency. // Note that this means overlays you want to be rtl need to be explicitly set to rtl. this.container.dir = 'ltr'; if (this.useCanvas) { var viewportSize = this._calculateCanvasSize(); this.canvas.width = viewportSize.x; this.canvas.height = viewportSize.y; } this.canvas.style.width = "100%"; this.canvas.style.height = "100%"; this.canvas.style.position = "absolute"; $.setElementOpacity( this.canvas, this.opacity, true ); // Allow pointer events to pass through the canvas element so implicit // pointer capture works on touch devices $.setElementPointerEventsNone( this.canvas ); $.setElementTouchActionNone( this.canvas ); // explicit left-align this.container.style.textAlign = "left"; this.container.appendChild( this.canvas ); this._checkForAPIOverrides(); }; /** @lends OpenSeadragon.DrawerBaseBase.prototype */ $.DrawerBase.prototype = { // Drawer implementaions must define the next four methods. These are called // by core OSD and/or public APIs, and forcing overrides (even for nullop methods) makes the // behavior of the implementations explicitly clear in the code. // Whether these have been overridden by child classes is checked in the // constructor (via _checkForAPIOverrides). /** * @param tiledImage the TiledImage that is ready to be drawn */ draw: function(tiledImage) { $.console.error('Drawer.draw must be implemented by child class'); }, /** * @returns {Boolean} True if rotation is supported. */ canRotate: function() { $.console.error('Drawer.canRotate must be implemented by child class'); }, /** * Destroy the drawer (unload current loaded tiles) */ destroy: function() { $.console.error('Drawer.destroy must be implemented by child class'); }, /** * Turns image smoothing on or off for this viewer. Note: Ignored in some (especially older) browsers that do not support this property. * * @function * @param {Boolean} [imageSmoothingEnabled] - Whether or not the image is * drawn smoothly on the canvas; see imageSmoothingEnabled in * {@link OpenSeadragon.Options} for more explanation. */ setImageSmoothingEnabled: function(imageSmoothingEnabled){ $.console.error('Drawer.setImageSmoothingEnabled must be implemented by child class'); }, /** * Optional public API to draw a rectangle (e.g. for debugging purposes) * Child classes can override this method if they wish to support this * @param {OpenSeadragon.Rect} rect */ drawDebuggingRect: function(rect) { $.console.warn('[drawer].drawDebuggingRect is not implemented by this drawer'); }, // Deprecated functions clear: function(){ $.console.warn('[drawer].clear() is deprecated. The drawer is responsible for clearing itself as needed before drawing tiles.'); }, // Private functions /** * @private * @inner * Ensures that child classes have provided implementations for public API methods * draw, canRotate, destroy, and setImageSmoothinEnabled. Throws an exception if the original * placeholder methods are still in place. */ _checkForAPIOverrides: function(){ if(this.draw === $.DrawerBase.prototype.draw){ throw("[drawer].draw must be implemented by child class"); } if(this.canRotate === $.DrawerBase.prototype.canRotate){ throw("[drawer].canRotate must be implemented by child class"); } if(this.destroy === $.DrawerBase.prototype.destroy){ throw("[drawer].destroy must be implemented by child class"); } if(this.setImageSmoothingEnabled === $.DrawerBase.prototype.setImageSmoothingEnabled){ throw("[drawer].setImageSmoothingEnabled must be implemented by child class"); } }, // Utility functions internal API /** * @private * @inner * Scale from OpenSeadragon viewer rectangle to drawer rectangle * (ignoring rotation) * @param {OpenSeadragon.Rect} rectangle - The rectangle in viewport coordinate system. * @returns {OpenSeadragon.Rect} Rectangle in drawer coordinate system. */ _viewportToDrawerRectangle: function(rectangle) { var topLeft = this.viewport.pixelFromPointNoRotate(rectangle.getTopLeft(), true); var size = this.viewport.deltaPixelsFromPointsNoRotate(rectangle.getSize(), true); return new $.Rect( topLeft.x * $.pixelDensityRatio, topLeft.y * $.pixelDensityRatio, size.x * $.pixelDensityRatio, size.y * $.pixelDensityRatio ); }, /** * @private * @inner * This function converts the given point from to the drawer coordinate by * multiplying it with the pixel density. * This function does not take rotation into account, thus assuming provided * point is at 0 degree. * @param {OpenSeadragon.Point} point - the pixel point to convert * @returns {OpenSeadragon.Point} Point in drawer coordinate system. */ _viewportCoordToDrawerCoord: function(point) { var vpPoint = this.viewport.pixelFromPointNoRotate(point, true); return new $.Point( vpPoint.x * $.pixelDensityRatio, vpPoint.y * $.pixelDensityRatio ); }, /** * @private * @inner * Calculate width and height of the canvas based on viewport dimensions * and pixelDensityRatio * @returns {Dictionary} {x, y} size of the canvas */ _calculateCanvasSize: function() { var pixelDensityRatio = $.pixelDensityRatio; var viewportSize = this.viewport.getContainerSize(); return { // canvas width and height are integers x: Math.round(viewportSize.x * pixelDensityRatio), y: Math.round(viewportSize.y * pixelDensityRatio) }; }, }; Object.defineProperty($.DrawerBase.prototype, "isOpenSeadragonDrawer", { get: function get() { return true; } }); }( OpenSeadragon ));