urho3d/Source/Engine/UI/DropDownList.h

//
// Copyright (c) 2008-2014 the Urho3D project.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//

#pragma once

#include "Menu.h"

namespace Urho3D
{

class ListView;

/// %Menu %UI element that displays a popup list view.
class URHO3D_API DropDownList : public Menu
{
    OBJECT(DropDownList)

public:
    /// Construct.
    DropDownList(Context* context);
    /// Destruct.
    ~DropDownList();
    /// Register object factory.
    static void RegisterObject(Context* context);

    /// Apply attribute changes that can not be applied immediately.
    virtual void ApplyAttributes();
    /// Return UI rendering batches.
    virtual void GetBatches(PODVector<UIBatch>& batches, PODVector<float>& vertexData, const IntRect& currentScissor);
    /// React to the popup being shown.
    virtual void OnShowPopup();
    /// React to the popup being hidden.
    virtual void OnHidePopup();
    /// React to editable status change.
    virtual void OnSetEditable();
    
    /// Add item to the end of the list.
    void AddItem(UIElement* item);
    /// Insert item to a specific position.
    void InsertItem(unsigned index, UIElement* item);
    /// Remove specific item.
    void RemoveItem(UIElement* item);
    /// Remove item at index.
    void RemoveItem(unsigned index);
    /// Remove all items.
    void RemoveAllItems();
    /// Set selection.
    void SetSelection(unsigned index);
    /// Set place holder text. This is the text shown when there is no selection in drop down list.
    void SetPlaceholderText(const String& text);
    /// Set whether popup should be automatically resized to match the dropdown button width.
    void SetResizePopup(bool enable);

    /// Return number of items.
    unsigned GetNumItems() const;
    /// Return item at index.
    UIElement* GetItem(unsigned index) const;
    /// Return all items.
    PODVector<UIElement*> GetItems() const;
    /// Return selection index, or M_MAX_UNSIGNED if none selected.
    unsigned GetSelection() const;
    /// Return selected item, or null if none selected.
    UIElement* GetSelectedItem() const;
    /// Return listview element.
    ListView* GetListView() const { return listView_; }
    /// Return selected item placeholder element.
    UIElement* GetPlaceholder() const { return placeholder_; }
    /// Return place holder text.
    const String& GetPlaceholderText() const;
    /// Return whether popup should be automatically resized.
    bool GetResizePopup() const { return resizePopup_; }

    /// Set selection attribute.
    void SetSelectionAttr(unsigned index);

protected:
    /// Filter implicit attributes in serialization process.
    virtual bool FilterImplicitAttributes(XMLElement& dest) const;
    /// Filter implicit attributes in serialization process.
    virtual bool FilterPopupImplicitAttributes(XMLElement& dest) const;

    /// Listview element.
    SharedPtr<ListView> listView_;
    /// Selected item placeholder element.
    SharedPtr<UIElement> placeholder_;
    /// Resize popup flag.
    bool resizePopup_;

private:
    /// Handle listview item click event.
    void HandleItemClicked(StringHash eventType, VariantMap& eventData);
    /// Handle a key press from the listview
    void HandleListViewKey(StringHash eventType, VariantMap& eventData);

    /// Selected item index attribute.
    unsigned selectionAttr_;
};

}