openseadragon/src/navigator.js

/*
 * OpenSeadragon - Navigator
 *
 * Copyright (C) 2009 CodePlex Foundation
 * Copyright (C) 2010-2013 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 Navigator
 * @classdesc The Navigator provides a small view of the current image as fixed
 * while representing the viewport as a moving box serving as a frame
 * of reference in the larger viewport as to which portion of the image
 * is currently being examined.  The navigator's viewport can be interacted
 * with using the keyboard or the mouse.
 *
 * @memberof OpenSeadragon
 * @extends OpenSeadragon.Viewer
 * @extends OpenSeadragon.EventSource
 * @param {Object} options
 */
$.Navigator = function( options ){

    var viewer      = options.viewer,
        _this = this,
        viewerSize,
        navigatorSize;

    //We may need to create a new element and id if they did not
    //provide the id for the existing element
    if( !options.id ){
        options.id              = 'navigator-' + $.now();
        this.element            = $.makeNeutralElement( "div" );
        options.controlOptions  = {
            anchor:           $.ControlAnchor.TOP_RIGHT,
            attachToViewer:   true,
            autoFade:         true
        };

        if( options.position ){
            if( 'BOTTOM_RIGHT' == options.position ){
               options.controlOptions.anchor = $.ControlAnchor.BOTTOM_RIGHT;
            } else if( 'BOTTOM_LEFT' == options.position ){
               options.controlOptions.anchor = $.ControlAnchor.BOTTOM_LEFT;
            } else if( 'TOP_RIGHT' == options.position ){
               options.controlOptions.anchor = $.ControlAnchor.TOP_RIGHT;
            } else if( 'TOP_LEFT' == options.position ){
               options.controlOptions.anchor = $.ControlAnchor.TOP_LEFT;
            } else if( 'ABSOLUTE' == options.position ){
               options.controlOptions.anchor = $.ControlAnchor.ABSOLUTE;
               options.controlOptions.top = options.top;
               options.controlOptions.left = options.left;
               options.controlOptions.height = options.height;
               options.controlOptions.width = options.width;
            }
        }

    } else {
        this.element            = document.getElementById( options.id );
        options.controlOptions  = {
            anchor:           $.ControlAnchor.NONE,
            attachToViewer:   false,
            autoFade:         false
        };
    }
    this.element.id         = options.id;
    this.element.className  += ' navigator';

    options = $.extend( true, {
        sizeRatio:     $.DEFAULT_SETTINGS.navigatorSizeRatio
    }, options, {
        element:                this.element,
        tabIndex:               -1, // No keyboard navigation, omit from tab order
        //These need to be overridden to prevent recursion since
        //the navigator is a viewer and a viewer has a navigator
        showNavigator:          false,
        mouseNavEnabled:        false,
        showNavigationControl:  false,
        showSequenceControl:    false,
        immediateRender:        true,
        blendTime:              0,
        animationTime:          0,
        autoResize:             options.autoResize,
        // prevent resizing the navigator from adding unwanted space around the image
        minZoomImageRatio:      1.0
    });

    options.minPixelRatio = this.minPixelRatio = viewer.minPixelRatio;

    $.setElementTouchActionNone( this.element );

    this.borderWidth = 2;
    //At some browser magnification levels the display regions lines up correctly, but at some there appears to
    //be a one pixel gap.
    this.fudge = new $.Point(1, 1);
    this.totalBorderWidths = new $.Point(this.borderWidth*2, this.borderWidth*2).minus(this.fudge);


    if ( options.controlOptions.anchor != $.ControlAnchor.NONE ) {
        (function( style, borderWidth ){
            style.margin        = '0px';
            style.border        = borderWidth + 'px solid #555';
            style.padding       = '0px';
            style.background    = '#000';
            style.opacity       = 0.8;
            style.overflow      = 'hidden';
        }( this.element.style, this.borderWidth));
    }

    this.displayRegion           = $.makeNeutralElement( "div" );
    this.displayRegion.id        = this.element.id + '-displayregion';
    this.displayRegion.className = 'displayregion';

    (function( style, borderWidth ){
        style.position      = 'relative';
        style.top           = '0px';
        style.left          = '0px';
        style.fontSize      = '0px';
        style.overflow      = 'hidden';
        style.border        = borderWidth + 'px solid #900';
        style.margin        = '0px';
        style.padding       = '0px';
        //TODO: IE doesnt like this property being set
        //try{ style.outline  = '2px auto #909'; }catch(e){/*ignore*/}

        style.background    = 'transparent';

        // We use square bracket notation on the statement below, because float is a keyword.
        // This is important for the Google Closure compiler, if nothing else.
        /*jshint sub:true */
        style['float']      = 'left'; //Webkit

        style.cssFloat      = 'left'; //Firefox
        style.styleFloat    = 'left'; //IE
        style.zIndex        = 999999999;
        style.cursor        = 'default';
    }( this.displayRegion.style, this.borderWidth ));

    this.displayRegionContainer = $.makeNeutralElement("div");
    this.displayRegionContainer.id = this.element.id + '-displayregioncontainer';
    this.displayRegionContainer.className = "displayregioncontainer";
    this.displayRegionContainer.style.width = "100%";
    this.displayRegionContainer.style.height = "100%";

    viewer.addControl(
        this.element,
        options.controlOptions
    );

    this._resizeWithViewer = options.controlOptions.anchor != $.ControlAnchor.ABSOLUTE &&
        options.controlOptions.anchor != $.ControlAnchor.NONE;

    if ( this._resizeWithViewer ) {
        if ( options.width && options.height ) {
            this.element.style.height = typeof ( options.height )  == "number" ? ( options.height + 'px' ) : options.height;
            this.element.style.width  = typeof ( options.width )  == "number" ? ( options.width + 'px' ) : options.width;
        } else {
            viewerSize = $.getElementSize( viewer.element );
            this.element.style.height = Math.round( viewerSize.y * options.sizeRatio ) + 'px';
            this.element.style.width  = Math.round( viewerSize.x * options.sizeRatio ) + 'px';
            this.oldViewerSize = viewerSize;
        }
        navigatorSize = $.getElementSize( this.element );
        this.elementArea = navigatorSize.x * navigatorSize.y;
    }

    this.oldContainerSize = new $.Point( 0, 0 );

    $.Viewer.apply( this, [ options ] );

    this.displayRegionContainer.appendChild(this.displayRegion);
    this.element.getElementsByTagName('div')[0].appendChild(this.displayRegionContainer);

    if (options.navigatorRotate) {
        options.viewer.addHandler("rotate", function (args) {
            _setTransformRotate(_this.displayRegionContainer, args.degrees);
            _setTransformRotate(_this.displayRegion, -args.degrees);
            _this.viewport.setRotation(args.degrees);
        });
    }

    // Remove the base class' (Viewer's) innerTracker and replace it with our own
    this.innerTracker.destroy();
    this.innerTracker = new $.MouseTracker({
        element:         this.element,
        dragHandler:     $.delegate( this, onCanvasDrag ),
        clickHandler:    $.delegate( this, onCanvasClick ),
        releaseHandler:  $.delegate( this, onCanvasRelease ),
        scrollHandler:   $.delegate( this, onCanvasScroll )
    });

    this.addHandler("reset-size", function() {
        if (_this.viewport) {
            _this.viewport.goHome(true);
        }
    });

    viewer.world.addHandler("item-index-change", function(event) {
        var item = _this.world.getItemAt(event.previousIndex);
        _this.world.setItemIndex(item, event.newIndex);
    });

    viewer.world.addHandler("remove-item", function(event) {
        var theirItem = event.item;
        var myItem = _this._getMatchingItem(theirItem);
        if (myItem) {
            _this.world.removeItem(myItem);
        }
    });

    this.update(viewer.viewport);
};

$.extend( $.Navigator.prototype, $.EventSource.prototype, $.Viewer.prototype, /** @lends OpenSeadragon.Navigator.prototype */{

    /**
     * Used to notify the navigator when its size has changed.
     * Especially useful when {@link OpenSeadragon.Options}.navigatorAutoResize is set to false and the navigator is resizable.
     * @function
     */
    updateSize: function () {
        if ( this.viewport ) {
            var containerSize = new $.Point(
                    (this.container.clientWidth === 0 ? 1 : this.container.clientWidth),
                    (this.container.clientHeight === 0 ? 1 : this.container.clientHeight)
                );

            if ( !containerSize.equals( this.oldContainerSize ) ) {
                this.viewport.resize( containerSize, true );
                this.viewport.goHome(true);
                this.oldContainerSize = containerSize;
                this.drawer.clear();
                this.world.draw();
            }
        }
    },

    /**
     * Used to update the navigator minimap's viewport rectangle when a change in the viewer's viewport occurs.
     * @function
     * @param {OpenSeadragon.Viewport} The viewport this navigator is tracking.
     */
    update: function( viewport ) {

        var viewerSize,
            newWidth,
            newHeight,
            bounds,
            topleft,
            bottomright;

        viewerSize = $.getElementSize( this.viewer.element );
        if ( this._resizeWithViewer && viewerSize.x && viewerSize.y && !viewerSize.equals( this.oldViewerSize ) ) {
            this.oldViewerSize = viewerSize;

            if ( this.maintainSizeRatio || !this.elementArea) {
                newWidth  = viewerSize.x * this.sizeRatio;
                newHeight = viewerSize.y * this.sizeRatio;
            } else {
                newWidth = Math.sqrt(this.elementArea * (viewerSize.x / viewerSize.y));
                newHeight = this.elementArea / newWidth;
            }

            this.element.style.width  = Math.round( newWidth ) + 'px';
            this.element.style.height = Math.round( newHeight ) + 'px';

            if (!this.elementArea) {
                this.elementArea = newWidth * newHeight;
            }

            this.updateSize();
        }

        if( viewport && this.viewport ) {
            bounds      = viewport.getBounds( true );
            topleft     = this.viewport.pixelFromPointNoRotate(bounds.getTopLeft(), false);
            bottomright = this.viewport.pixelFromPointNoRotate(bounds.getBottomRight(), false)
                .minus( this.totalBorderWidths );

            //update style for navigator-box
            var style = this.displayRegion.style;
            style.display = this.world.getItemCount() ? 'block' : 'none';

            style.top    = Math.round( topleft.y ) + 'px';
            style.left   = Math.round( topleft.x ) + 'px';

            var width = Math.abs( topleft.x - bottomright.x );
            var height = Math.abs( topleft.y - bottomright.y );
            // make sure width and height are non-negative so IE doesn't throw
            style.width  = Math.round( Math.max( width, 0 ) ) + 'px';
            style.height = Math.round( Math.max( height, 0 ) ) + 'px';
        }

    },

    // overrides Viewer.addTiledImage
    addTiledImage: function(options) {
        var _this = this;

        var original = options.originalTiledImage;
        delete options.original;

        var optionsClone = $.extend({}, options, {
            success: function(event) {
                var myItem = event.item;
                myItem._originalForNavigator = original;
                _this._matchBounds(myItem, original, true);

                original.addHandler('bounds-change', function() {
                    _this._matchBounds(myItem, original);
                });
            }
        });

        return $.Viewer.prototype.addTiledImage.apply(this, [optionsClone]);
    },

    // private
    _getMatchingItem: function(theirItem) {
        var count = this.world.getItemCount();
        var item;
        for (var i = 0; i < count; i++) {
            item = this.world.getItemAt(i);
            if (item._originalForNavigator === theirItem) {
                return item;
            }
        }

        return null;
    },

    // private
    _matchBounds: function(myItem, theirItem, immediately) {
        var bounds = theirItem.getBounds();
        myItem.setPosition(bounds.getTopLeft(), immediately);
        myItem.setWidth(bounds.width, immediately);
    }
});

/**
 * @private
 * @inner
 * @function
 */
function onCanvasClick( event ) {
    if ( event.quick && this.viewer.viewport ) {
        this.viewer.viewport.panTo(this.viewport.pointFromPixel(event.position));
        this.viewer.viewport.applyConstraints();
    }
}

/**
 * @private
 * @inner
 * @function
 */
function onCanvasDrag( event ) {
    if ( this.viewer.viewport ) {
        if( !this.panHorizontal ){
            event.delta.x = 0;
        }
        if( !this.panVertical ){
            event.delta.y = 0;
        }
        this.viewer.viewport.panBy(
            this.viewport.deltaPointsFromPixels(
                event.delta
            )
        );
    }
}


/**
 * @private
 * @inner
 * @function
 */
function onCanvasRelease( event ) {
    if ( event.insideElementPressed && this.viewer.viewport ) {
        this.viewer.viewport.applyConstraints();
    }
}


/**
 * @private
 * @inner
 * @function
 */
function onCanvasScroll( event ) {
    /**
     * Raised when a scroll event occurs on the {@link OpenSeadragon.Viewer#navigator} element (mouse wheel, touch pinch, etc.).
     *
     * @event navigator-scroll
     * @memberof OpenSeadragon.Viewer
     * @type {object}
     * @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised this event.
     * @property {OpenSeadragon.MouseTracker} tracker - A reference to the MouseTracker which originated this event.
     * @property {OpenSeadragon.Point} position - The position of the event relative to the tracked element.
     * @property {Number} scroll - The scroll delta for the event.
     * @property {Boolean} shift - True if the shift key was pressed during this event.
     * @property {Object} originalEvent - The original DOM event.
     * @property {?Object} userData - Arbitrary subscriber-defined object.
     */
    this.viewer.raiseEvent( 'navigator-scroll', {
        tracker: event.eventSource,
        position: event.position,
        scroll: event.scroll,
        shift: event.shift,
        originalEvent: event.originalEvent
    });

    //dont scroll the page up and down if the user is scrolling
    //in the navigator
    return false;
}

/**
    * @function
    * @private
    * @param {Object} element
    * @param {Number} degrees
    */
function _setTransformRotate (element, degrees) {
    element.style.webkitTransform = "rotate(" + degrees + "deg)";
    element.style.mozTransform = "rotate(" + degrees + "deg)";
    element.style.msTransform = "rotate(" + degrees + "deg)";
    element.style.oTransform = "rotate(" + degrees + "deg)";
    element.style.transform = "rotate(" + degrees + "deg)";
}

}( OpenSeadragon ));