wg_dropdown.cpp

一个小巧的嵌入式图形系统wGUI, 可以用VC编译

// wg_dropdown.cpp
//
// CDropDown class implementation
//
//
// Copyright (c) 2002 Rob Wiskow
// [e-mail]
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//


#include "wgui_include_config.h"
#include "wg_dropdown.h"
#include "wg_message_server.h"
#include "wg_resources.h"


namespace wGui
{

CDropDown::CDropDown(const CRect& WindowRect, CWindow* pParent, bool bAllowEdit, unsigned int iItemHeight, CFontEngine* pFontEngine) :
	CWindow(WindowRect, pParent),
	m_bAllowEdit(bAllowEdit)
{
  m_sClassName = "CDropDown";
	m_pEditBox = new CEditBox(CRect(WindowRect.TopLeft(), CPoint(WindowRect.Right() - WindowRect.Height(), WindowRect.Bottom())),
		this, pFontEngine);
	if (!m_bAllowEdit)
	{
		m_pEditBox->SetReadOnly(true);
		// Override the normal read-only BG color
		m_pEditBox->SetBGColor(COLOR_WHITE);
	}

	// We create the listbox with the root window (probably a CView object) as it's parent, so that it gets the OnMouseButtonDown/Up properly
	m_pListBox = new CListBox(CRect(WindowRect.BottomLeft(), CPoint(WindowRect.Right(), WindowRect.Bottom() + iItemHeight * 5 + 1)),
		GetAncestor(ROOT), true, iItemHeight, pFontEngine);
	m_pListBox->SetVisible(false);
	m_pListBox->SetDropDown(this);

	m_pDropButton = new CPictureButton(
		CRect(CPoint(WindowRect.Right() - WindowRect.Height() + 1, WindowRect.Top()), WindowRect.BottomRight()),
		this, CwgBitmapResourceHandle(WGRES_DOWN_ARROW_BITMAP));
	CMessageServer::Instance().RegisterMessageClient(this, CMessage::MOUSE_BUTTONDOWN);
	CMessageServer::Instance().RegisterMessageClient(this, CMessage::CTRL_LCLICK);
	CMessageServer::Instance().RegisterMessageClient(this, CMessage::CTRL_VALUECHANGE);
}


CDropDown::~CDropDown(void)
{
	// The listbox is parented by the root window, so we need to delete it by hand
	delete m_pListBox;
}


void CDropDown::SetWindowText(std::string sWindowText)
{
	m_pEditBox->SetWindowText(sWindowText);
}


bool CDropDown::HandleMessage(CMessage* pMessage)
{
	bool bHandled = false;
	CRect SubRect(m_WindowRect);
	SubRect.Grow(-3);

	if (pMessage)
	{
		switch(pMessage->MessageType())
		{
		case CMessage::MOUSE_BUTTONDOWN:
		{
			CMouseMessage* pMouseMessage = dynamic_cast<CMouseMessage*>(pMessage);
			if (pMouseMessage->Button == CMouseMessage::LEFT)
			{
				if (m_pListBox->IsVisible() && m_pDropButton->GetWindowRect().HitTest(pMouseMessage->Point) != CRect::RELPOS_INSIDE
					&& m_pListBox->GetWindowRect().HitTest(pMouseMessage->Point) != CRect::RELPOS_INSIDE)
				{
					HideListBox();
				}
			}
			break;
		}
		case CMessage::CTRL_LCLICK:
		{
			if (pMessage->Destination() == this)
			{
				if (pMessage->Source() == m_pDropButton)
				{
					if (m_pListBox->IsVisible())
					{
						HideListBox();
					}
					else
					{
						ShowListBox();
					}
					bHandled = true;
				}
			}
			break;
		}
		case CMessage::CTRL_VALUECHANGE:
		{
			TIntMessage* pCtrlMessage = dynamic_cast<TIntMessage*>(pMessage);
			if (pCtrlMessage && pMessage->Destination() == this)
			{
				if (pCtrlMessage->Source() == m_pListBox)
				{
					const SListItem& ListItem = m_pListBox->GetItem(pCtrlMessage->Value());
					SetWindowText(ListItem.sItemText);
					HideListBox();
					CMessageServer::Instance().QueueMessage(new TIntMessage(CMessage::CTRL_VALUECHANGE, m_pParentWindow, this, 0));
					bHandled = true;
				}
				else if (pCtrlMessage->Source() == m_pEditBox)
				{
					m_pListBox->SetAllSelections(false);
					HideListBox();
					CMessageServer::Instance().QueueMessage(new TIntMessage(CMessage::CTRL_VALUECHANGE, m_pParentWindow, this, 0));
					bHandled = true;
				}
			}
			break;
		}
		default :
			bHandled = CWindow::HandleMessage(pMessage);
			break;
		}
	}

	return bHandled;
}


void CDropDown::ShowListBox(void)
{
	if (!m_pListBox->IsVisible())
	{
		// This makes sure the ListBox is at the top of the order so it gets first shot at the OnMouseButtonDown/Up
		m_pListBox->SetNewParent(m_pListBox->GetAncestor(PARENT));
		m_pListBox->SetVisible(true);
		m_pListBox->StartDrawProc();
	}
}


void CDropDown::HideListBox(void)
{
	if (m_pListBox->IsVisible())
	{
		m_pListBox->SetVisible(false);
		CMessageServer::Instance().QueueMessage(new CMessage(CMessage::APP_PAINT, 0, this));
	}
}

}