Create an Owner Draw Menu - Step by Step

Environment: Visual C++ 6

For the owner draw control, I found the most difficult part is the menu. I have searched through the Web, but I only found some difficult examples. In this article, I will demonstrates the step for drawing our own menu. We'll make a menu class and a class for holding the menu data.

Let's take the SDI MFC application as an example. In the File Menu, click New to add a new project. Then, choose MFC Application Wizard (exe). In the project name, type in OwnerdrawMenu (just an example), and then click OK. In step one of the MFC App Wizard, choose Single Document. After pressing Finish, you are brought to the "New Project Information" page. You'll ignore this page, so press OK.

Let's make our menu data class first. It is just a simple class which has one CString member variable to hold the menu item's caption.

Right-click "OwnerdrawMenu classes" in the ClassView; then choose "New Class." For the class type, choose "Generic Class." In the "Name" editbox, type in "CMyMenuData" (just an example). Finally, click OK.

Add a public CString member variable which is called "m_strCaption"(just an example).

Next, we have to make a menu class. Right-click "OwnerdrawMenu classes" in the ClassView; then choose "New Class." For the class type, choose "Generic Class." In the "Name" editbox, type in "CMyMenu" (just an example). In the "Base Classes" section, type in "CMenu" in the "Derived From" editbox and choose "public" in the "As" listbox.

Our menu class is added. It's time to give some content to it. We will add three functions, some include statements, and two member variables in the CMyMenu header file (such as MyMenu.h).

#include "MyMenuData.h"
#include <vector>
using namespace std;

public:
  //a recursive function to change all the sub menu and menu items
  // to have the owner draw style
  void ChangeToOwnerDraw(CMyMenu* pMyMenu);
  //use for drawing
  virtual void DrawItem( LPDRAWITEMSTRUCT lpDrawItemStruct );
  //use for giving the dimension of the menu item
  virtual void MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct);
private:
  vector<CMyMenu*> rgpMyMenu;         //use to handle sub menu
  vector<CMyMenuData*> rgpMyMenuData; //use to handle my menu data

We have to add the implementation in MyMenu.cpp, as shown below.

void CMyMenu::ChangeToOwnerDraw(CMyMenu *pMyMenu)
{
  CString str;                  //use to hold the caption temporarily
  CMyMenu* pMenu;               //use to hold the sub menu
  CMyMenuData* pMenuData;       //use to hold the menu data
  //get the number of the menu items of the parent menu
  int iMenuCount = pMyMenu->GetMenuItemCount();
  UINT nID; //use to hold the identifier of the menu items
  for (int i=0; i<iMenuCount; i++)
  {
    //get the caption of the menu item
    pMyMenu->GetMenuString(i, str, MF_BYPOSITION);
    pMenu = 0;       //reset pointer for safety
    pMenuData = 0;   //reset pointer for safety
    pMenuData = new CMyMenuData;
    pMenuData->m_strCaption = str;
    rgpMyMenuData.push_back(pMenuData);

    if (pMyMenu->GetSubMenu(i)) //if the parent menu has sub menu
    {
      pMyMenu->ModifyMenu(i, 
                             MF_BYPOSITION | MF_OWNERDRAW, 
                             0, 
                             (LPCTSTR)pMenuData);
      pMenu = new CMyMenu;
      rgpMyMenu.push_back(pMenu);
      HMENU hMenu = pMyMenu->GetSubMenu(i)->GetSafeHmenu();
      pMenu->Attach(hMenu);
      ChangeToOwnerDraw(pMenu);
    }
    else
    {
      nID = pMyMenu->GetMenuItemID(i);
      pMyMenu->ModifyMenu(i,
                             MF_BYPOSITION | MF_OWNERDRAW, 
                             (UINT)nID, 
                             (LPCTSTR)pMenuData);
    }
  }
}

void CMyMenu::MeasureItem(LPMEASUREITEMSTRUCT lpMeasureItemStruct)
{
  CMyMenuData* pMyMenuData = 
          (CMyMenuData*)lpMeasureItemStruct->itemData;
  //get the caption of the menu item
  CString str = pMyMenuData->m_strCaption;
  //assign the height of the menu item
  lpMeasureItemStruct->itemHeight = 23;0
  //assign the width of the menu item
  lpMeasureItemStruct->itemWidth = str.GetLength()*7;
}

void CMyMenu::DrawItem(LPDRAWITEMSTRUCT lpDrawItemStruct)
{
  CDC* pDC = CDC::FromHandle(lpDrawItemStruct->hDC);
  //draw an orange background
  pDC->FillSolidRect(&lpDrawItemStruct->rcItem, 
                     RGB(255,150,0));

  //if the menu item is selected
  if ((lpDrawItemStruct->itemState & ODS_SELECTED) &&
    (lpDrawItemStruct->itemAction & (ODA_SELECT | ODA_DRAWENTIRE)))
  {
    //draw a blue background
    pDC->FillSolidRect(&lpDrawItemStruct->rcItem, 
                          RGB(0,150,255));
  }

  CMyMenuData* pMyMenuData = 
       (CMyMenuData*)lpDrawItemStruct->itemData;

  CString str = pMyMenuData->m_strCaption;
  //draw the caption of the menu item
  pDC->TextOut(lpDrawItemStruct->rcItem.left,
                  lpDrawItemStruct->rcItem.top, str);
}

CMyMenu::~CMyMenu()
{
  int iCount = rgpMyMenu.size();
  for (int i=0; i<iCount; i++)
  {
    rgpMyMenu[i]->Detach();
    delete rgpMyMenu[i];
    rgpMyMenu[i] = 0;
  }
  iCount = rgpMyMenuData.size();
  for (i=0; i<iCount; i++)
  {
    delete rgpMyMenuData[i];
    rgpMyMenuData[i] = 0;
  }
}

After we have added a lot of things to CMyMenu class, it's the time to use it in the CMainFrame class. Add the following to the MainFrm.h.

#include "MyMenu.h"

private:
  CMyMenu* pMyMenu;

At the end of the CMainFrame::OnCreate function, but before the line "return 0;", add the following code.

pMyMenu = new CMyMenu;
HMENU hMenu = ::GetMenu(GetSafeHwnd());
pMyMenu->Attach(hMenu);
SetMenu(pMyMenu);
pMyMenu->ChangeToOwnerDraw(pMyMenu);

We have to add a message handler for OnDestory, too. Right-click CMainFrame in the ClassView; choose "Add Windows Message Handler." Add WM_DESTORY handler. The code of the OnDestroy function is as the following.

void CMainFrame::OnDestroy() 
{
  CFrameWnd::OnDestroy();

  if (pMyMenu)
  {
    pMyMenu->Detach();
    delete pMyMenu;
    pMyMenu = 0;
  }
}

We have finished our long adventure. Press F7 for our final fire.

Downloads

Download demo project - 33 Kb



Comments

  • Article helped me a lot

    Posted by pvaan kumar on 02/27/2013 09:42am

    thanks for the article. It is very useful and neat.

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: September 10, 2014 @ 11:00 a.m. ET / 8:00 a.m. PT Modern mobile applications connect systems-of-engagement (mobile apps) with systems-of-record (traditional IT) to deliver new and innovative business value. But the lifecycle for development of mobile apps is also new and different. Emerging trends in mobile development call for faster delivery of incremental features, coupled with feedback from the users of the app "in the wild". This loop of continuous delivery and continuous feedback is …

  • The first phase of API management was about realizing the business value of APIs. This next wave of API management enables the hyper-connected enterprise to drive and scale their businesses as API models become more complex and sophisticated. Today, real world product launches begin with an API program and strategy in mind. This API-first approach to development will only continue to increase, driven by an increasingly interconnected web of devices, organizations, and people. To support this rapid growth, …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds