Full-Screen Dialog Boxes

  • Article

To assist programmers in creating full-size dialog boxes, the Pocket PC shell implements a function named SHInitDialog. As the name implies, the function should be called during the handling of the WM_INITDIALOG message. The function is prototyped as

BOOL SHInitDialog (PSHINITDLGINFO pshidi);

The function takes a single parameter, a pointer to an SHINITDLGINFO structure defined as

typedef struct tagSHINITDIALOG{ 
    DWORD dwMask; 
    HWND hDlg; 
    DWORD dwFlags; 
} SHINITDLGINFO;

The dwMask field must be set to the single flag currently supported, SHIDIM_FLAGS. The hDlg field should be set to the window handle of the dialog. The third parameter, dwFlags, specifies a number of different initialization options. The SHIDIF_DONEBUTTON specifies that the navigation bar across the top of the screen contain an OK button in the upper right corner. This flag is typically set because the user interface guidelines specify that dialogs have an OK button in the navigation bar, and the guidelines specify that there be no Cancel button. While one could argue with this specification, the user interface provides no automatic way to provide a Cancel button.

The SHIDIF_SIPDOWN flag closes the SIP when the dialog is displayed. This flag should be set for informational dialogs that have no text input fields. Note that the absence of this flag doesn't automatically display the SIP. It simply means that the state of the SIP remains unchanged when the dialog box is displayed.

Three other flags can be set in the dwFlags field:

  • SHIDIF_SIZEDLG
  • SHIDIF_SIZEDLGFULLSCREEN
  • SHIDIF_FULLSCREENNOMENUBAR

These flags deal with how the dialog box will be sized. The SHIDIF_SIZEDLG flag tells the system to size the dialog box depending on the state of the SIP. If the SIP is displayed, the dialog box will be sized to fit above the SIP. If the SIP is hidden, the dialog will be sized to fit just above the menu bar. If, however, you have a floating SIP, the dialog box doesn't size correctly. This is a rare occurrence, because neither of the bundled input methods that ship with the Pocket PC can be undocked. However, the example input method in Chapter 18 does have the ability to float.

The SHIDIF_SIZEDLGFULLSCREEN and SHIDIF_FULLSCREENNOMENUBAR flags size the dialog to fit the entire screen regardless of the state of the SIP. The difference between the two flags is that SHIDIF_FULLSCREENNOMENUBAR does not leave room for the menu bar at the bottom of the screen.

This topic is from Programming Microsoft Windows CE, Third Edition, by Douglas Boling, published by Microsoft Press. © 2003 by Douglas McConnaughey Boling. Reprinted here by permission of the author.