WTL Tool Bar Drop-Down Extension






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Apr 28, 2000

157916

1976
An article on extending the tool bar control using the Window Template Library
Introduction
I needed a toolbar with drop down arrows so that I could place some pop-up menus on them. Initially I tried handling the notification messages from within the parent window. This became a huge mess and was just plain ugly looking. So I decided instead to create my own custom toolbar control. The process is quite simple so I'll get right to the code:
How it works
1. We needed to retrieve the notification messages from the parent window. Now, we don't just want to go and reflect all of the notification messages since we don't want to have to handle all of them. So we create a contained window, with which we can selectively chose which notification messages were going to handle.
CContainedWindow m_wndParent; //... CToolBarCtrlExImpl() : m_wndParent(this, 1), m_pDropDownButtons(NULL), m_bImagesVisible(false), m_bAnimate(false), m_clrMask(RGB(192, 192, 192)) { //... } //... LRESULT OnCreate(UINT uMsg, WPARAM wParam, LPARAM lParam, BOOL& /*bHandled*/) { //... // Subclass parent window CWindow wndParent = GetParent(); CWindow wndTopLevelParent = wndParent.GetTopLevelParent(); m_wndParent.SubclassWindow(wndTopLevelParent); //... }
2. We've now got a copy of the parent window and are receiving all of its messages. Next we need to define in the message map which messages were going to process.
BEGIN_MSG_MAP(CToolBarCtrlExImpl) //... ALT_MSG_MAP(1) // Parent window messages NOTIFY_CODE_HANDLER(TBN_DROPDOWN, OnParentDropDown) NOTIFY_CODE_HANDLER(TBN_HOTITEMCHANGE, OnParentHotItemChange) END_MSG_MAP()
Notice that were using ALT_MSG_MAP(1)
. ATL supports multiple
message maps, so all messages that belong to the parent window are now been
pumped through here. By the way, the parent window still receives all these
messages, we're just taking a peek at them and using the ones we need.
The following code is the current message handlers in the toolbar class:
LRESULT OnParentDropDown(int /*idCtrl*/, LPNMHDR pnmh, BOOL& bHandled) { LPNMTOOLBAR lpnmtb = (LPNMTOOLBAR)pnmh; // Check if this is from us if (pnmh->hwndFrom != m_hWnd) { bHandled = FALSE; return TBDDRET_NODEFAULT; } _DropDownButton* pb = FindDropDownButton(lpnmtb->iItem); RECT rc; GetRect(pb->uIdButton, &rc); ClientToScreen(&rc); if (pb && pb->uIdMenu) if (DoDropDownMenu(pb->uIdMenu, &rc)) <- See History for comments return TBDDRET_DEFAULT; return TBDDRET_NODEFAULT; } // Do not hot track if application in background LRESULT OnParentHotItemChange(int /*idCtrl*/, LPNMHDR pnmh, BOOL& bHandled) { LPNMTBHOTITEM lpnmhi = (LPNMTBHOTITEM)pnmh; // Check if this is from us if (pnmh->hwndFrom != m_hWnd) { bHandled = FALSE; return 0; } DWORD dwProcessID; ::GetWindowThreadProcessId(::GetActiveWindow(), &dwProcessID); if ((!m_wndParent.IsWindowEnabled() || ::GetCurrentProcessId() != dwProcessID)) return 1; else { bHandled = FALSE; return 0; } }
Updates
I just finished adding bitmaps to the menu, so that all menu items that would usually display a bitmap, will.
How to use
In MainFrm.h declare a CToolBarCtrlEx and in the OnCreate handler initialize it like the below example.
class CMainFrame : ... { //... CToolBarCtrlEx m_wndToolBar; //... LRESULT OnCreate(UINT /*uMsg*/, WPARAM /*wParam*/, LPARAM /*lParam*/, BOOL& /*bHandled*/) { //... // HWND hWndToolBar = CreateSimpleToolBarCtrl(m_hWnd, IDR_MAINFRAME, FALSE, ATL_SIMPLE_TOOLBAR_PANE_STYLE); HWND hWndToolBar = m_wndToolBar.Create(m_hWnd, rcDefault, NULL, ATL_SIMPLE_TOOLBAR_PANE_STYLE); m_wndToolBar.LoadToolBar(IDR_MAINFRAME); // Load the toolbar m_wndToolBar.LoadMenuImages(IDR_MAINFRAME); // Load all the menu images were going to need m_wndToolBar.AddDropDownButton(ID_FILE_NEW, IDR_MAINFRAME); // Add some drop-down buttons m_wndToolBar.AddDropDownButton(ID_FILE_OPEN, IDR_POPUP_OPEN); m_wndToolBar.AddDropDownButton(ID_EDIT_PASTE, IDR_POPUP_PASTE); //... } //... };
Thanks to Paul DiLascia for the code to add drop-down menus to toolbar buttons. (MSJ - 1997)
That's it!.
History
Version 1.1
- Revised the drop down method and made it a virtual function so that it can be overridden for custom handling.
- Added bitmaps to the menu items.
Version 1.0
- Added drop down menus to the drop-down buttons.