Form Designer

// ValuePicker.cpp: implementation of the CValuePicker class.
//
// Author : David Shepherd
//			Copyright (c) 2002, DaeDoe-Software
//
/////////////////////////////////////////////////////////////////////////////

#include "stdafx.h"
#include "ValuePicker.h"

/////////////////////////////////////////////////////////////////////////////
// CValuePickerValue

CValuePickerValue::CValuePickerValue()
{
	// initialise everything
}

CValuePickerValue::~CValuePickerValue()
{
	// clean up
}

/////////////////////////////////////////////////////////////////////////////
// CValuePicker

CValuePicker::CValuePicker() : m_List(this,VP_MSG_MAP_LIST)
{
	// initialise everything
	m_RunMessageLoop=TRUE;
}

CValuePicker::~CValuePicker()
{
	// clean up
}

CFontHandle CValuePicker::GetFont()
{
	// return the value picker font
	CFontHandle hFont=(HFONT)GetStockObject(DEFAULT_GUI_FONT);
	if(hFont==NULL)
	{
		throw std::exception();
	}
	return hFont;
}

void CValuePicker::SetSizeAndPosition(const CPoint &TopRight,DWORD Width)
{
	// get the list box item height
	DWORD ItemHeight=m_List.GetItemHeight(0);
	if(ItemHeight==LB_ERR)
	{
		throw std::exception();
	}
	// get the required list box height
	DWORD ListBoxHeight=min(8,m_Values.size())*ItemHeight;
	// allow room for the border
	ListBoxHeight+=2*GetSystemMetrics(SM_CYBORDER);

	// get the value picker rect
	CRect ValuePickerRect(0,0,Width,ListBoxHeight);
	// position the top right corner
	ValuePickerRect.OffsetRect(
		TopRight.x-ValuePickerRect.right+1,TopRight.y-ValuePickerRect.top);
	// prevent screen overrun
	CRect ScreenRect(
		0,0,GetSystemMetrics(SM_CXSCREEN),GetSystemMetrics(SM_CYSCREEN));
	// todo : allow for the task bar
	ValuePickerRect=ForceRectIntoRect(ScreenRect,ValuePickerRect);

	// size and position the value picker
	if(SetWindowPos(NULL,ValuePickerRect,SWP_NOZORDER)==FALSE)
	{
		throw std::exception();
	}
}

void CValuePicker::SelectStartValue()
{
	// select the initial value
	for(long l=0; l<(long)m_Values.size(); l++)
	{
		// compare values
		if(m_Values[l].m_Value!=m_Value)
		{
			continue;
		}
		// found a match
		if(m_List.SetCurSel(l)==LB_ERR)
		{
			throw std::exception();
		}
		break;	// done
	}
}

BOOL CValuePicker::PickValue(const CWindow &Parent,const CPoint &TopRight,DWORD Width)
{
TRY
	// reinitialise everything to allow object reuse
	m_RunMessageLoop=TRUE;
	// create the value picker window (invisible)
	if(Create(Parent,CRect(0,0,0,0),_T(""),WS_POPUP|WS_CLIPCHILDREN)==NULL)
	{
		throw std::exception();
	}
	// size and position the value picker
	SetSizeAndPosition(TopRight,Width);
	// select the initial value
	SelectStartValue();
	// show the value picker
	(void)ShowWindow(SW_SHOW);
	// run the message loop
	while(m_RunMessageLoop)
	{
		// get the next message
		// todo : check for the WM_QUIT message
		MSG Message;
		(void)GetMessage(&Message,NULL,0,0);
		// process the message
		(void)TranslateMessage(&Message);
		(void)DispatchMessage(&Message);
	}
CATCH_ALL
	// clean up
	if(IsWindow())
	{
		(void)DestroyWindow();
	}
	return Caught ? FALSE : TRUE;	// return TRUE on success
}

LRESULT CValuePicker::OnCreate(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
TRY
	// create the list box
	if(m_List.Create(*this,CRect(0,0,0,0),_T(""),
		// standard window styles
		WS_CHILD|WS_VISIBLE|WS_BORDER|WS_VSCROLL|
		// list box styles
		LBS_NOTIFY|LBS_NOINTEGRALHEIGHT|LBS_OWNERDRAWFIXED,
		// extended window styles
		0,
		// id
		VP_IDC_LIST)==NULL)
	{
		throw std::exception();
	}
	// add all values to the list box
	for(long l=0; l<(long)m_Values.size(); l++)
	{
		// add by vector index
		LRESULT Result=m_List.AddString((LPCTSTR)l);
		if(Result==LB_ERR or Result==LB_ERRSPACE)
		{
			throw std::exception();
		}
	}
CATCH_ALL
	return Caught ? -1 : 0;	// fail creation on error
}

LRESULT CValuePicker::OnSize(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
TRY
	// get the client rect
	CRect ClientRect(0,0,0,0);
	if(GetClientRect(ClientRect)==FALSE)
	{
		throw std::exception();
	}
	// size the list box to fill the entire client area
	if(m_List.SetWindowPos(NULL,ClientRect,SWP_NOZORDER)==FALSE)
	{
		throw std::exception();
	}
CATCH_ALL
	return 0;
}

LRESULT CValuePicker::OnMeasureItem(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
TRY
	// should be for the list box
	ATLASSERT(wParam==VP_IDC_LIST);

	// get the measure item struct
	MEASUREITEMSTRUCT *pMeasureItemStruct=(MEASUREITEMSTRUCT *)lParam;
	// initialise the item height to something sensible
	DWORD MinItemHeight=8;
	pMeasureItemStruct->itemHeight=MinItemHeight;
	// create the display information context
	CDC dc=CreateIC(_T("Display"),NULL,NULL,NULL);
	if(dc==NULL)
	{
		throw std::exception();
	}
	// get the font height
	LOGFONT lf;
	if(GetObject(GetFont(),sizeof(LOGFONT),&lf)==0)
	{
		throw std::exception();
	}
	DWORD FontHeight=abs(lf.lfHeight);
	// set the item height
	DWORD ItemHeight=max(MinItemHeight,POINT_SIZE_TO_PIXELS(dc,FontHeight));
	pMeasureItemStruct->itemHeight=ItemHeight;
CATCH_ALL
	return TRUE;
}

LRESULT CValuePicker::OnDrawItem(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
TRY
	USES_CONVERSION;

	// should be for the list box
	ATLASSERT(wParam==VP_IDC_LIST);

	// get the draw item struct
	DRAWITEMSTRUCT *pDrawItemStruct=(DRAWITEMSTRUCT *)lParam;
	// wrap the device context and save the state
	CDCHandle hDC=pDrawItemStruct->hDC;
	CAutoDCState AutoDCState(hDC);
	// get the item rect
	CRect ItemRect=pDrawItemStruct->rcItem;
	// determine if the item is selected
	BOOL IsSelected=
		(pDrawItemStruct->itemState & ODS_SELECTED) ? TRUE : FALSE;

	// get the item value
	CValuePickerValue Value=m_Values[pDrawItemStruct->itemData];

	// set the font
	if(hDC.SelectFont(GetFont())==NULL)
	{
		throw std::exception();
	}
	// set the background color
	COLORREF BackColor=GetSysColor(
		IsSelected ? COLOR_HIGHLIGHT : COLOR_WINDOW);
	if(hDC.SetBkColor(BackColor)==CLR_INVALID)
	{
		throw std::exception();
	}
	// set the foreground color
	COLORREF ForeColor=GetSysColor(
		IsSelected ? COLOR_HIGHLIGHTTEXT : COLOR_WINDOWTEXT);
	if(hDC.SetTextColor(ForeColor)==CLR_INVALID)
	{
		throw std::exception();
	}
	// fill in the background
	hDC.FillSolidRect(ItemRect,BackColor);
	// draw the value name
	if(hDC.DrawText(W2CT(Value.m_Name.c_str()),
		-1,ItemRect,DT_SINGLELINE|DT_VCENTER|DT_NOPREFIX)==0)
	{
		throw std::exception();
	}
CATCH_ALL
	return TRUE;
}

LRESULT CValuePicker::OnActivate(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
TRY
	// if the window is being deactivated
	if(LOWORD(wParam)==WA_INACTIVE)
	{
		// get the window being activated
		CWindow ActiveWindow=(HWND)lParam;
		// if the value picker is no longer active
		if(ActiveWindow!=*this and ActiveWindow!=m_List)
		{
			// hide the value picker immediately
			(void)ShowWindow(SW_HIDE);
			// shut down
			m_RunMessageLoop=FALSE;
		}
	}
CATCH_ALL
	return 0;
}

LRESULT CValuePicker::OnKillFocus(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& bHandled)
{
TRY
	// get the window receiving focus
	CWindow FocusWindow=(HWND)wParam;
	// if the value picker no longer has the focus
	if(FocusWindow!=*this and FocusWindow!=m_List)
	{
		// hide the value picker immediately
		(void)ShowWindow(SW_HIDE);
		// shut down
		m_RunMessageLoop=FALSE;
	}
CATCH_ALL
	return 0;
}

LRESULT CValuePicker::OnSelChangeList(WORD wNotifyCode, WORD wID, HWND hWndCtl, BOOL& bHandled)
{
TRY
	// get the selected item
	DWORD ItemIndex=m_List.GetCurSel();
	if(ItemIndex==LB_ERR)
	{
		throw std::exception();
	}
	// update the value
	m_Value=m_Values[ItemIndex].m_Value;
	// shut down
	m_RunMessageLoop=FALSE;
CATCH_ALL
	return 0;
}