th.js

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/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
 * See the License for the specific language governing rights and
 * limitations under the License.
 *
 * The Original Code is Bespin.
 *
 * The Initial Developer of the Original Code is Mozilla.
 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Bespin Team ([e-mail])
 *
 * ***** END LICENSE BLOCK ***** */

dojo.provide("th.th");  

/*
    Constants
 */ 
dojo.mixin(th, {
    VERTICAL: "v",
    HORIZONTAL: "h"    
});

/*
    Event bus; all listeners and events pass through a single global instance of this class.
 */ 
dojo.declare("th.Bus", null, {
    constructor: function() {
        // map of event name to listener; listener contains a selector, function, and optional context object
        this.events = {};
    },

    // register a listener with an event
    bind: function(event, selector, listenerFn, listenerContext) {
        var listeners = this.events[event];
        if (!listeners) {
            listeners = [];
            this.events[event] = listeners;
        }
        selector = dojo.isArray(selector) ? selector : [ selector ];
        for (var z = 0; z < selector.length; z++) {
            for (var i = 0; i < listeners.length; i++) {
                if (listeners[i].selector == selector[z] && listeners[i].listenerFn == listenerFn) return;
            }
            listeners.push({ selector: selector[z], listenerFn: listenerFn, context: listenerContext });
        }
    },

    // removes any listeners whose selectors have the *same identity* as the passed selector
    unbind: function(selector) {
        for (var event in this.events) {
            var listeners = this.events[event];

            for (var i = 0; i < listeners.length; i++) {
                if (listeners[i].selector === selector) {
                    this.events[event] = dojo.filter(listeners, function(item){ return item != listeners[i]; });                    
                    listeners = this.events[event];
                    i--;
                }
            }
        }
    },

    // notify all listeners of an event
    fire: function(eventName, eventDetails, component) {
        var listeners = this.events[eventName];
        if (!listeners || listeners.length == 0) return;

        // go through each listener registered for the fired event and check if the selector matches the component for whom
        // the event was fired; if there is a match, dispatch the event
        for (var i = 0; i < listeners.length; i++) {
            // if the listener selector is a string...
            if (listeners[i].selector.constructor == String) {
                // check if the string starts with a hash, indicating that it should match by id
                if (listeners[i].selector.charAt(0) == "#") {
                    if (component.id == listeners[i].selector.substring(1)) {
                        this.dispatchEvent(eventName, eventDetails, component, listeners[i]);
                    }
                // otherwise check if it's the name of the component class
                } else if (listeners[i].selector == component.declaredClass) {
                    this.dispatchEvent(eventName, eventDetails, component, listeners[i]);
                }
            // otherwise check if the selector is the current component
            } else if (listeners[i].selector == component) {
                this.dispatchEvent(eventName, eventDetails, component, listeners[i]);
            }
        }
    },

    // invokes the listener function
    dispatchEvent: function(eventName, eventDetails, component, listener) {
        eventDetails.thComponent = component;

        // check if there is listener context; if so, execute the listener function using that as the context
        if (listener.context) {
            listener.listenerFn.apply(listener.context, [ eventDetails ]);
        } else {
            listener.listenerFn(eventDetails);
        }
    }
});

// create the global event bus
th.global_event_bus = new th.Bus();

dojo.declare("th.Scene", th.helpers.EventHelpers, { 
    bus: th.global_event_bus,

    css: {},

    sheetCount: 0,
    currentSheet: 0,
    cssLoaded: false,
    renderRequested: false,

    constructor: function(canvas) {
        this.canvas = canvas;

        var self = this;
        dojo.connect(window, "resize", function(){
            self.render();
        }); 
        
        this.root = new th.components.Panel({ id: "root", style: {
//            backgroundColor: "pink" // for debugging         
        } });
        this.root.scene = this; 
        
        var testCanvas = document.createElement("canvas");
        this.scratchContext = testCanvas.getContext("2d");
        bespin.util.canvas.fix(this.scratchContext);

        var self = this;
        
        dojo.connect(window, "mousedown", function(e) {
            self.wrapEvent(e, self.root);

            self.mouseDownComponent = e.thComponent;

            th.global_event_bus.fire("mousedown", e, e.thComponent);
        });

        dojo.connect(window, "dblclick", function(e) {
            self.wrapEvent(e, self.root);

            th.global_event_bus.fire("dblclick", e, e.thComponent);
        });

        dojo.connect(window, "click", function(e) {
            self.wrapEvent(e, self.root);

            th.global_event_bus.fire("click", e, e.thComponent);
        });

        dojo.connect(window, "mousemove", function(e) {
            self.wrapEvent(e, self.root);

            th.global_event_bus.fire("mousemove", e, e.thComponent);

            if (self.mouseDownComponent) {
                self.addComponentXY(e, self.root, self.mouseDownComponent);
                th.global_event_bus.fire("mousedrag", e, self.mouseDownComponent);
            }
        });

        dojo.connect(window, "mouseup", function(e) {
            if (!self.mouseDownComponent) return;

            self.addComponentXY(e, self.root, self.mouseDownComponent);
            th.global_event_bus.fire("mouseup", e, self.mouseDownComponent);

            delete self.mouseDownComponent;
        });

        this.parseCSS();
    },

    render: function() { 
        if (!this.cssLoaded) { 
            this.renderRequested = true;
            return;
        }
        this.layout();
        this.paint();
    },

    layout: function() {
        if (this.root) {
            this.root.bounds = { x: 0, y: 0, width: this.canvas.width, height: this.canvas.height };
            this.root.layoutTree();
        }
    },

    paint: function(component) {        
        if (!this.cssLoaded) {
            this.renderRequested = true;
            return;
        }

        if (!component) component = this.root;

        //if (component === this.root) console.log("root paint");

        if (component) {
            if (!component.opaque && component.parent) {
                return this.paint(component.parent);
            }

            var ctx = this.canvas.getContext("2d");
            bespin.util.canvas.fix(ctx);

            ctx.save();

            var parent = component.parent;
            var child = component;
            while (parent) {
                ctx.translate(child.bounds.x, child.bounds.y);
                child = parent;
                parent = parent.parent;
            }
             
            ctx.clearRect(0, 0, component.bounds.width, component.bounds.height);
            ctx.beginPath();
            ctx.rect(0, 0, component.bounds.width, component.bounds.height);
            ctx.closePath();
            ctx.clip(); 
            component.paint(ctx);  
            
            ctx.restore();
        }
    },

    parseCSS: function() { 
        var links = [];   
        var s, l = document.getElementsByTagName('link');
		for (var i=0; i < l.length; i++){ 
		    s = l[i];
			if (s.rel.toLowerCase().indexOf('stylesheet') >= 0&&s.href) {
			    links.push(s.href);
			}
		} 
        if (links.length == 0) {
            this.cssLoaded = true;
            return;
        }
        this.sheetCount = links.length;
        dojo.forEach(links, function(link) {            
            dojo.xhrGet({
                url: link, 
                load: dojo.hitch(this, function(response) {
                    this.processCSS(response);
                })
            });
        }, this);
    },

    processCSS: function(stylesheet) {
        this.css = new th.css.CSSParser().parse(stylesheet, this.css);  

        if (++this.currentSheet == this.sheetCount) {
            this.cssLoaded = true;
            if (this.renderRequested) {
                this.render();
                this.renderRequested = false;
            }
        }
    }
});

dojo.declare("th.Border", th.helpers.ComponentHelpers, {
    constructor: function(parms) {
        if (!parms) parms = {};
        this.style = parms.style || {};
        this.attributes = parms.attributes || {};
    },

    getInsets: function() {
        return this.emptyInsets();
    },

    paint: function(ctx) {}
});   
    
dojo.declare("th.Component", th.helpers.ComponentHelpers, {
    constructor: function(parms) { 
        if (!parms) parms = {};
        this.bounds = parms.bounds || {};
        this.style = parms.style || {};
        this.attributes = parms.attributes || {};
        this.id = parms.id;
        this.border = parms.border;
        this.opaque = parms.opaque || true;
    
        this.bus = th.global_event_bus; 
    },
    
    // used to obtain a throw-away canvas context for performing measurements, etc.; may or may not be the same canvas as that used to draw the component
    getScratchContext: function() {
        var scene = this.getScene();
        if (scene) return scene.scratchContext;
    },
    
    getPreferredHeight: function(width) {},
    
    getPreferredWidth: function(height) {},
    
    getInsets: function() {
        return (this.border) ? this.border.getInsets() : this.emptyInsets();
    },
    
    paint: function(ctx) {
        console.log("default component paint");
    },
    
    repaint: function() {
        this.getScene().paint(this);
    }
});

dojo.declare("th.Container", [th.Component, th.helpers.ContainerHelpers], {
    constructor: function() {       
        this.children = [];
    },
    
    add: function() {
        for (var z = 0; z < arguments.length; z++) {
            component = dojo.isArray(arguments[z]) ? arguments[z] : [ arguments[z] ]; 
            this.children = this.children.concat(component);
            for (var i = 0; i < component.length; i++) {
                component[i].parent = this;
            }
        }
    },

    remove: function() {
        for (var z = 0; z < arguments.length; z++) {
            component = dojo.isArray(arguments[z]) ? arguments[z] : [ arguments[z] ];
            for (var i = 0; i < component.length; i++) {
                var old_length = this.children.length;
                this.children = dojo.filter(this.children, function(item){ return item != component[i]; });

                // if the length of the array has changed since I tried to remove the current component, assume it was removed and clear the parent
                if (old_length != this.children.length) delete component[i].parent;
            }
        }
    },

    paint: function(ctx) {
        if (this.shouldPaint()) {
            this.paintSelf(ctx);
            this.paintChildren(ctx);
        }
    },

    paintSelf: function(ctx) {},

    paintChildren: function(ctx) {
        for (var i = 0; i < this.children.length; i++ ) {
            if (!this.children[i].shouldPaint()) continue;

            if (!this.children[i].bounds) {
                // console.log("WARNING: child " + i + " (type: " + this.children[i].declaredClass + ", id: " + this.children[i].id + ") of parent with id " + this.id + " of type " + this.declaredClass + " has no bounds and could not be painted");
                continue;
            }

            ctx.save();
            try {
                ctx.translate(this.children[i].bounds.x, this.children[i].bounds.y);
            } catch (error) {
                // console.log("WARNING: child " + i + " (type: " + this.children[i].declaredClass + ", id: " + this.children[i].id + ") of parent with id " + this.id + " of type " + this.declaredClass + " has malformed bounds and could not be painted");
                // console.log(this.children[i].bounds);
                ctx.restore();
                continue;
            }

            try {
                if (!this.children[i].style["noClip"]) {
                    ctx.beginPath();
                    ctx.rect(0, 0, this.children[i].bounds.width, this.children[i].bounds.height);
                    ctx.closePath();
                    ctx.clip();
                }
            } catch(ex) {
                // console.log("Bounds problem");
                // console.log(this.children[i].declaredClass);
                // console.log(this.children[i].bounds);
            }

            ctx.save();
            this.children[i].paint(ctx);
            ctx.restore();

            if (this.children[i].style.border) {
                this.children[i].style.border.component = this.children[i];
                ctx.save();
                this.children[i].style.border.paint(ctx);
                ctx.restore();
            }

            ctx.restore();
        }
    },

    // lays out this container and any sub-containers
    layoutTree: function() {
        this.layout();
        for (var i = 0; i < this.children.length; i++) {  
            if (this.children[i].layoutTree) this.children[i].layoutTree();
        }
    },

    layout: function() {
        var d = this.d();
        if (this.children.length > 0) {
            var totalWidth = this.bounds.width - d.i.w;
            var individualWidth = totalWidth / this.children.length;
            for (var i = 0; i < this.children.length; i++) {
                this.children[i].bounds = { x: (i * individualWidth) + d.i.l, y: d.i.t, width: individualWidth, height: this.bounds.height - d.i.h };
            }
        }
    },

    render: function() {
        this.layoutTree();
        this.repaint();
    }
});