/**

 * Copyright (c) 2009-2010 Symbian Foundation and/or its subsidiary(-ies).

 * All rights reserved.

 * This component and the accompanying materials are made available

 * under the terms of the License "Eclipse Public License v1.0"

 * which accompanies this distribution, and is available

 * at the URL "http://www.eclipse.org/legal/epl-v10.html".

 *

 * Initial Contributors:

 * Contributors:

 */

///////////////////////////////////////////////////////////////////////////////

// The Control class is an abstract base class for all user interface controls.

// Constructor.

function Control(id, caption) {

    if (id != UI_NO_INIT_ID) {

        this.init(id, caption);

    }

}

// Control inherits from UIElement.

Control.prototype = new UIElement(UI_NO_INIT_ID);

// The view that control belongs to.

Control.prototype.view = null;

// Is the control focused?

Control.prototype.focused = false;

// Is the pointer over this control?

Control.prototype.hovering = false;

// The element hierarchy in a control is as follows:

//

// rootElement

//     assemblyElement

//         captionElement

//         controlElement

//

// The assembly element groups the portion of a control that typically handle

// the visual effects for focus and hover states. Having a separate root and

// assembly elements allows other elements to be added to a control without

// them being affected by the CSS rules of the assembly element.

// The assembly element of this control.

Control.prototype.assemblyElement = null;

// The caption of this control; null if none.

Control.prototype.caption = null;

// The caption element of this control.

Control.prototype.captionElement = null;

// The control element of this control.

Control.prototype.controlElement = null;

// Initializer - called from constructor.

Control.prototype.init = function(id, caption) {

    uiLogger.debug("Control.init(" + id + ", " + caption + ")");

    // call superclass initializer

    UIElement.prototype.init.call(this, id);

    // create assembly, caption and control elements

    this.assemblyElement = document.createElement("div");

    this.captionElement = document.createElement("div");

    this.assemblyElement.appendChild(this.captionElement);

    this.controlElement = document.createElement("div");

    this.assemblyElement.appendChild(this.controlElement);

    this.rootElement.appendChild(this.assemblyElement);

    // set the caption

    // style is not updated because the subclass will update the style later

    // when it has completely initialized the component

    this.setCaption(caption, true);

};

// Returns the caption; null if none.

Control.prototype.getCaption = function() {

    return this.caption;

};

// Sets the caption; null if none.

Control.prototype.setCaption = function(caption, noStyleUpdate) {

    uiLogger.debug("Control.setCaption(" + caption + ")");

    // set the display style

    this.captionElement.style.display = (caption == null) ? "none" : "block";

    // set the caption

    this.caption = caption;

    this.captionElement.innerHTML = (caption == null) ? "" : caption;

    // update style

    if (!noStyleUpdate) {

        this.updateStyleFromState();

    }

};

// Returns the enabled state.

// Override this in subclasses as required to implement the state change.

Control.prototype.isEnabled = function() {

    return false;

};

// Sets the enabled state.

// Override this in subclasses as required to implement the state change.

Control.prototype.setEnabled = function(enabled) {

    uiLogger.debug("Control.setEnabled(" + enabled + ")");

};

// Returns the focusable state for the control.

// Defaults focusable if enabled - override this in subclasses as required.

Control.prototype.isFocusable = function() {

    return this.isEnabled();

};

// Returns the focused state for the control.

Control.prototype.isFocused = function() {

    return this.focused;

};

// Sets the focused state for the control.

// Note: This may not always succeed.

// Override this in subclasses as required to implement the state change.

Control.prototype.setFocused = function(focused) {

    uiLogger.debug("Control.setFocused(" + focused + ")");

    // note that this.focused gets set as a result of focusStateChanged() being called

    // rather than setting it explicitly here

};

// Called when the focus state has changed for this control.

Control.prototype.focusStateChanged = function(focused) {

    uiLogger.debug("Control.focusStateChanged(" + focused + ")");

    if (this.focused != focused) {

        this.focused = focused;

        // let the view know about the focus change

        if (this.view != null) {

            this.view.focusedControlChanged(focused ? this : null);

        }

        // update the style from the current state

        this.updateStyleFromState();

        // notify event listeners

        this.fireEvent(this.createEvent("FocusStateChanged", focused));

    }

};

// Called when the hover state has changed for this control.

Control.prototype.hoverStateChanged = function(hovering) {

    uiLogger.debug("Control.hoverStateChanged(" + hovering + ")");

    if (this.hovering != hovering) {

        this.hovering = hovering;

        // update the style from the current state

        this.updateStyleFromState();

        // notify event listeners

        this.fireEvent(this.createEvent("HoverStateChanged", hovering));

    }

};

// Helper method that returns the state name for the current state.

Control.prototype.getStyleStateName = function() {

    var focusable = this.isFocusable();

    if (focusable && this.focused) {

        return "Focus";

    } else if (focusable && this.hovering) {

        return "Hover";

    } else if (!this.isEnabled()) {

        return "Disabled";

    } else {

        return "Normal";

    }

};

// Resets the state tracking for focus and hover.

// Override this in subclasses as required to implement the state reset.

Control.prototype.resetFocusState = function() {

    uiLogger.debug("Control.resetFocusState()");

    this.hovering = false;

    this.focused = false;

    this.updateStyleFromState();

};

// Helper function that sets a classname for an element.

// Only sets the class name if it actually is different from the current value.

Control.prototype.setClassName = function(element, className) {

    if (element.className != className) {

        element.className = className;

    }

};

// Updates the style of the control to reflects the state of the control.

// Override this in subclasses as required to implement the state change.

Control.prototype.updateStyleFromState = function() {

    uiLogger.debug("Control.updateStyleFromState()");

};