source: Dev/trunk/src/client/dojox/mobile/ComboBox.js

define([
        "dojo/_base/kernel",
        "dojo/_base/declare",
        "dojo/_base/lang",
        "dojo/_base/window",
        "dojo/dom-geometry",
        "dojo/dom-style",
        "dojo/dom-attr",
        "dojo/window",
        "dojo/touch",
        "dijit/form/_AutoCompleterMixin",
        "dijit/popup",
        "./_ComboBoxMenu",
        "./TextBox",
        "./sniff"
], function(kernel, declare, lang, win, domGeometry, domStyle, domAttr, windowUtils, touch, AutoCompleterMixin, popup, ComboBoxMenu, TextBox, has){
        kernel.experimental("dojox.mobile.ComboBox"); // should be using a more native search-type UI

        return declare("dojox.mobile.ComboBox", [TextBox, AutoCompleterMixin], {
                // summary:
                //              A non-templated auto-completing text box widget.

                // dropDownClass: [protected extension] String
                //              Name of the drop-down widget class used to select a date/time.
                //              Should be specified by subclasses.
                dropDownClass: "dojox.mobile._ComboBoxMenu",

                // initially disable selection since iphone displays selection handles
                // that makes it hard to pick from the list
                
                // selectOnClick: Boolean
                //              Flag which enables the selection on click.
                selectOnClick: false,
                
                // autoComplete: Boolean
                //              Flag which enables the auto-completion.
                autoComplete: false,

                // dropDown: [protected] Widget
                //              The widget to display as a popup. This widget *must* be
                //              defined before the startup function is called.
                dropDown: null,

                // maxHeight: [protected] int
                //              The maximum height for the drop-down.
                //              Any drop-down taller than this value will have scrollbars.
                //              Set to -1 to limit the height to the available space in the viewport.
                maxHeight: -1,

                // dropDownPosition: [const] String[]
                //              This variable controls the position of the drop-down.
                //              It is an array of strings with the following values:
                //
                //              - before: places drop down to the left of the target node/widget, or to the right in
                //                the case of RTL scripts like Hebrew and Arabic
                //              - after: places drop down to the right of the target node/widget, or to the left in
                //                the case of RTL scripts like Hebrew and Arabic
                //              - above: drop down goes above target node
                //              - below: drop down goes below target node
                //
                //              The list is positions is tried, in order, until a position is found where the drop down fits
                //              within the viewport.
                dropDownPosition: ["below","above"],

                _throttleOpenClose: function(){
                        // summary:
                        //              Prevents the open/close in rapid succession.
                        // tags:
                        //              private
                        if(this._throttleHandler){
                                this._throttleHandler.remove();
                        }
                        this._throttleHandler = this.defer(function(){ this._throttleHandler = null; }, 500);
                },

                _onFocus: function(){
                        // summary:
                        //              Shows drop-down if the user is selecting Next/Previous from the virtual keyboard.
                        // tags:
                        //              private
                        this.inherited(arguments);
                        if(!this._opened && !this._throttleHandler){
                                this._startSearchAll(); 
                        }

                        if(has("windows-theme")) {
                                this.domNode.blur();
                        }
                },

                onInput: function(e){
                        this._onKey(e);
                        this.inherited(arguments);
                },

                _setListAttr: function(v){
                        // tags:
                        //              private
                        this._set('list', v); // needed for Firefox 4+ to prevent HTML5 mode
                },

                closeDropDown: function(){
                        // summary:
                        //              Closes the drop down on this widget
                        // tags:
                        //              protected

                        this._throttleOpenClose();
                        if(this.endHandler){
                                this.disconnect(this.startHandler);
                                this.disconnect(this.endHandler);
                                this.disconnect(this.moveHandler);
                                clearInterval(this.repositionTimer);
                                this.repositionTimer = this.endHandler = null;
                        }
                        this.inherited(arguments);
                        domAttr.remove(this.domNode, "aria-owns");
                        domAttr.set(this.domNode, "aria-expanded", "false");
                        popup.close(this.dropDown);
                        this._opened = false;

                        // Remove disable attribute to make input element clickable after context menu closed
                        if(has("windows-theme") && this.domNode.disabled){
                                this.defer(function(){
                                        this.domNode.removeAttribute("disabled");
                                }, 300);
                        }

                },

                openDropDown: function(){
                        // summary:
                        //              Opens the dropdown for this widget. To be called only when this.dropDown
                        //              has been created and is ready to display (that is, its data is loaded).
                        // returns:
                        //              Returns the value of popup.open().
                        // tags:
                        //              protected

                        var wasClosed = !this._opened;
                        var dropDown = this.dropDown,
                                ddNode = dropDown.domNode,
                                aroundNode = this.domNode,
                                self = this;
                                
                        domAttr.set(dropDown.domNode, "role", "listbox");
                        domAttr.set(this.domNode, "aria-expanded", "true");
                        if(dropDown.id){
                                domAttr.set(this.domNode, "aria-owns", dropDown.id);
                        }

                        if(has('touch')){
                                win.global.scrollBy(0, domGeometry.position(aroundNode, false).y); // don't call scrollIntoView since it messes up ScrollableView
                        }

                        // TODO: isn't maxHeight dependent on the return value from popup.open(),
                        // i.e., dependent on how much space is available (BK)

                        if(!this._preparedNode){
                                this._preparedNode = true;
                                // Check if we have explicitly set width and height on the dropdown widget dom node
                                if(ddNode.style.width){
                                        this._explicitDDWidth = true;
                                }
                                if(ddNode.style.height){
                                        this._explicitDDHeight = true;
                                }
                        }

                        // Code for resizing dropdown (height limitation, or increasing width to match my width)
                        var myStyle = {
                                display: "",
                                overflow: "hidden",
                                visibility: "hidden"
                        };
                        if(!this._explicitDDWidth){
                                myStyle.width = "";
                        }
                        if(!this._explicitDDHeight){
                                myStyle.height = "";
                        }
                        domStyle.set(ddNode, myStyle);

                        // Figure out maximum height allowed (if there is a height restriction)
                        var maxHeight = this.maxHeight;
                        if(maxHeight == -1){
                                // limit height to space available in viewport either above or below my domNode
                                // (whichever side has more room)
                                var viewport = windowUtils.getBox(),
                                        position = domGeometry.position(aroundNode, false);
                                maxHeight = Math.floor(Math.max(position.y, viewport.h - (position.y + position.h)));
                        }

                        // Attach dropDown to DOM and make make visibility:hidden rather than display:none
                        // so we call startup() and also get the size
                        popup.moveOffScreen(dropDown);

                        if(dropDown.startup && !dropDown._started){
                                dropDown.startup(); // this has to be done after being added to the DOM
                        }
                        // Get size of drop down, and determine if vertical scroll bar needed
                        var mb = domGeometry.position(this.dropDown.containerNode, false);
                        var overHeight = (maxHeight && mb.h > maxHeight);
                        if(overHeight){
                                mb.h = maxHeight;
                        }

                        // Adjust dropdown width to match or be larger than my width
                        mb.w = Math.max(mb.w, aroundNode.offsetWidth);
                        domGeometry.setMarginBox(ddNode, mb);

                        var retVal = popup.open({
                                parent: this,
                                popup: dropDown,
                                around: aroundNode,
                                orient: has("windows-theme") ? ["above"] : this.dropDownPosition,
                                onExecute: function(){
                                        self.closeDropDown();
                                },
                                onCancel: function(){
                                        self.closeDropDown();
                                },
                                onClose: function(){
                                        self._opened = false;
                                }
                        });
                        this._opened=true;

                        if(wasClosed){
                                var     isGesture = false,
                                        skipReposition = false,
                                        active = false,
                                        wrapper = dropDown.domNode.parentNode,
                                        aroundNodePos = domGeometry.position(aroundNode, false),
                                        popupPos = domGeometry.position(wrapper, false),
                                        deltaX = popupPos.x - aroundNodePos.x,
                                        deltaY = popupPos.y - aroundNodePos.y,
                                        startX = -1, startY = -1;

                                // touchstart isn't really needed since touchmove implies touchstart, but
                                // mousedown is needed since mousemove doesn't know if the left button is down or not
                                this.startHandler = this.connect(win.doc.documentElement, touch.press,
                                        function(e){
                                                skipReposition = true;
                                                active = true;
                                                isGesture = false;
                                                startX = e.clientX;
                                                startY = e.clientY;
                                        }
                                );
                                this.moveHandler = this.connect(win.doc.documentElement, touch.move,
                                        function(e){
                                                skipReposition = true;
                                                if(e.touches){
                                                        active = isGesture = true; // touchmove implies touchstart
                                                }else if(active && (e.clientX != startX || e.clientY != startY)){
                                                        isGesture = true;
                                                }
                                        }
                                );
                                this.clickHandler = this.connect(dropDown.domNode, "onclick",
                                        function(){
                                                skipReposition = true;
                                                active = isGesture = false; // click implies no gesture movement
                                        }
                                );
                                this.endHandler = this.connect(win.doc.documentElement, "onmouseup",//touch.release,
                                        function(){
                                                this.defer(function(){ // allow onclick to go first
                                                        skipReposition = true;
                                                        if(!isGesture && active){ // if click without move, then close dropdown
                                                                this.closeDropDown();
                                                        }
                                                        active = false;
                                                });
                                        }
                                );
                                this.repositionTimer = setInterval(lang.hitch(this, function(){
                                        if(skipReposition){ // don't reposition if busy
                                                skipReposition = false;
                                                return;
                                        }
                                        var     currentAroundNodePos = domGeometry.position(aroundNode, false),
                                                currentPopupPos = domGeometry.position(wrapper, false),
                                                currentDeltaX = currentPopupPos.x - currentAroundNodePos.x,
                                                currentDeltaY = currentPopupPos.y - currentAroundNodePos.y;
                                        // if the popup is no longer placed correctly, relocate it
                                        if(Math.abs(currentDeltaX - deltaX) >= 1 || Math.abs(currentDeltaY - deltaY) >= 1){ // Firefox plays with partial pixels
                                                domStyle.set(wrapper, { left: parseInt(domStyle.get(wrapper, "left")) + deltaX - currentDeltaX + 'px', top: parseInt(domStyle.get(wrapper, "top")) + deltaY - currentDeltaY + 'px' });
                                        }
                                }), 50); // yield a short time to allow for consolidation for better CPU throughput
                        }

                        // We need to disable input control in order to prevent opening the soft keyboard in IE
                        if(has("windows-theme")){
                                this.domNode.setAttribute("disabled", true);
                        }

                        return retVal;
                },

                postCreate: function(){
                        this.inherited(arguments);
                        this.connect(this.domNode, "onclick", "_onClick");
                        domAttr.set(this.domNode, "role", "combobox");
                        domAttr.set(this.domNode, "aria-expanded", "false");
                },

                destroy: function(){
                        if(this.repositionTimer){
                                clearInterval(this.repositionTimer);
                        }
                        this.inherited(arguments);
                },

                _onClick: function(/*Event*/ e){
                        // tags:
                        //              private
                        
                        // throttle clicks to prevent double click from doing double actions
                        if(!this._throttleHandler){
                                if(this.opened){
                                        this.closeDropDown();
                                }else{
                                        this._startSearchAll();
                                }
                        }
                }
        });
});