Getting Started
Introduction
Sample Programs
IDEs
History
Advice
Mini-Tutorial
Tutorials
Code Snippets

Resources
Web Sites
More Tutorials
Forums
Vendors/Tools
Books
Magazines
Newsletters
NewsGroups
User Groups
Talk Shows
Blogs

Controls
Overview
Button
Check3State
Checkbox
ComboBox
Frame
Graphic
Image
ImageX
ImgButton
ImgButtonX
Label
Line
ListBox
ListView
Option
Progress Bar
Scrollbar
StatusBar
TAB
TextBox
Toolbar
TreeView

GBIC >> PowerBASIC >> Tutorials >> Controls >> ImageX Control

PowerBASIC Information Center Tutorials
These tutorials were written to help you get a quick, but thorough, understanding of PowerBASIC - the scope of the language as well as it's specific capabilities.

Introduction       Projects       Language           Messages       Functions           Advanced
  • Overview
  • Examples
  • IDE
  • Compilation
  • Distribution
  • Project Files
  • DDT Windows
  • Controls
  • Menus
  • Dialogs  
  • Help Files
  • Resources  
  • Templates  
  • Project Shell  
  • Syntax
  • Operators
  • Data Types
  • Variables
  • Scope
  • Declarations  
  • Procedures
  • Flow Control
  • Windows
  • Messages
  • Callbacks
  • Mouse
  • Keyboard
  • Dialogs
  • Controls
  • Subclassing
  • Arithmetic
  • Trig  
  • Strings
  • Arrays
  • Date/Time
  • Printing
  • Files
  • Folders
  • Keyboard
  • Mouse
  • Sound
  • System
  • Error Traps
  • Debugging
  • Objects
  • Graphics
  • Databases
  • API
  • DLLs
  • ASM
  • Threads
  • ImageX Control
    The imagex control displays an image. The image is re-sized to fit the control. The control is not re-sized. The image must come from a resource file.

    • Syntax:
      Control Add ImageX, hDlg, id&, image$, x, y, xx, yy, _
                                             style&, extsytle& CALL callback
      

    • Source Code Example:
      This short example creates a complete application with a single imagex control. When clicked, the imagex control responds with a message. This tutorial page discusses most of the statements used, however the DDT, Controls, Messages, and Callback tutorials provide background information that may be helpful in understanding the example.

         #Compile Exe
         #Include "Win32API.inc"
         #Resource "pb-test.pbr"
         Global hDlg As Dword
         Function PBMain() As Long
            Dialog New Pixels, 0, "ImageX Test",300,300,200,200, _
                                            %WS_SysMenu, 0 To hDlg
            Control Add ImageX, hDlg, 100,"cowgirl", 50,50,100,100, %SS_Notify
            Dialog Show Modal hDlg Call DlgProc
         End Function
      
         CallBack Function DlgProc() As Long
            If Cb.Msg = %WM_Command And Cb.Ctl = 100 And _
                              Cb.CtlMsg = %STN_Clicked Then
               MsgBox "Pushed!"
            End If
         End Function  
      

      In this example, the image "cowgirl" is stored in a resource file, available from here. Also note that the #INCLUDE "Win32API.inc" is required because it contains the %STN_CLICKED message named constant.

      An additional example of a callback function is provided further down this page.

    • Visual Examples:
      And here are a few examples of what you can do with the imagex control in PowerBASIC. Variations on the Control Add ImageX statement were used to create the examples. In some cases, other Control statements were used to modify the results.

      There are few options. You can display the image at it's normal size, a smaller size, or an increased size.

    Arguments
    The Control Add statement is used to create all new controls. Here are the statement's arguments and any special significance to the imagex control.

    • hDlg
      The dialog handle to which the imagex control is to be added. The value was returned by the DIALOG NEW statement.

    • id&
      The id& argument is a control identifier assigned by the programmer. It must be a value of 1-65535. Values of 100+ are suggested, as PowerBASIC pre-assigns identifiers with special meaning. Numeric equates are suggested over the use of literal values.

    • image$
      The name of an image from a resource file is used in image$, such as "cowgirl". Or, the integer identifier from the resource file may be used, entered into image$ as "#100".

    • x,y and xx,yy
      The integer x,y and xx,yy dimensions use the same units as the parent dialog. (x,y) is the upper/left coordinates of the control. (xx,yy) is the width/height of the control.

    • style& and extstyle&
      The style& and extstyle& arguments (listed below) are optional. If not supplied, default values are used (see the table below). If values are supplied, they completely replace default values (i.e., the entered values are not in addition to the default values).

    • CALL
      The "CALL callback" section is optional. If not supplied, the callback function of the parent dialog is used. An example callback function for imagex controls is provided further down this page. The #MESSAGE COMMAND compiler directive can be used to prevent sending %WS_NOTIFY messages to the callback function. By default, both %WS_NOTIFY and %WS_COMMAND messages are sent.

    Usage Notes
    As noted earlier, images must come from PowerBASIC resource files.

    Note that the #INCLUDE "Win32API.inc" is required because it contains the %STN_CLICKED message named constant.

    The %SS_NOTIFY style must be included to received the %stn_click and %stn_dblclk notifications.

    ImageX Control-Specific PowerBASIC Statements
    Although PowerBASIC provides control-specific statements for some controls (Treeview, Imagelist, ...), there are no IMAGEX PowerBASIC statements.

    Messages, Notifications, Styles, and ExtSstyles
    There are four types of named constants in the following table. All are pulled from the MSDN web site.

    • Notifications - event notifications a control receives
    • Messages - controls may send these
    • Styles - affect the visual look of a control
    • ExtStyles - additional values that affect the visual look

    The first column contains control-specific named constants and the second column contains generic window named constants (imagex controls are windows).

    Also, if the PowerBASIC Help file has an entry on the value, it is highlighted in yellow. If the value was noted in PowerBASIC Help as a default value, it is also shown in bold text.

    In the values for notifications, descriptions starting with -n and -c refer to events received through the %wm_notify and %wm_command messages. By default, PowerBASIC controls can receive both of these messages.

       

    And here is a short description of many of the named constants corresponding to notifications, styles, and extstyle - particularly those discussed in the PowerBASIC Help topics.

        %ss_bitmap             - display only bitmap images
        %ss_icon               - display only icon images
        %ss_notify             - sends %stn_clicked/%stn_dblclk messages
        %ss_sunken             - draw half-sunken border
        %stn_clicked           -c mouse click
        %stn_dblclk            -c double slick
        %stn_disable           -c when control has been disabled
        %stn_enable            -c when control has been enabled
        %wm_ctlcolorstatic     -  about to be drawn
        %ws_ex_clientedge      - apply sunken edge border
        %ws_ex_left            - generic left-aligned properties
        %ws_ex_right           - generic right-aligned properties
        %ws_ex_staticedge      - apply 3D border
        %ws_ex_transparent     - draw controls/windows beneath control first
        %ws_group              - starts/ends group. use %ws_tabstop style.
    

    Callback Function
    A control can have its own callback function, or use the parent dialog callback function.

    A control callback function should return TRUE to indicate it has processed the message. This prevents unnecessarily calling the dialog callback function, which will process the message if no control callback function is available, or if the control callback function returns FALSE.

    By default, both %WM_COMMAND and %WM_NOTIFY messages are received. However, if the #MESSAGE COMMAND compiler directive is invoked, the %WM_NOTIFY messages will not be available.

    In addition, %ss_notify must be included in style& to receive the %stn_clicked and %stn_dblclk messages.

    Here's a sample imagex control callback function.

       CallBack Function cbImageX()
          Select Case CB.MSG
             Case %WM_COMMAND
                Select Case CB.CTLMSG
                   Case %stn_clicked
                   Case %stn_dblclk
                   Case %stn_disable
                   Case %stn_enable
             End Select
          End Select
       End Function
    

    In each Case section, add the statements the application needs to respond to the event. Also, be sure to add "Function=1" as appropriate to indicate that the event was handled by the callback function.

    CONTROL Statement Syntax
    The following table lists the various Control statements (except the ADD statements). Most, but not all, can be used with the imagex control. A one-line description of the statement and then its syntax are presented.

      CONTROL DISABLEdisable
      hDlg, id&
      CONTROL ENABLEenable hDlg, id&
      CONTROL GET CHECKcheck state hDlg, id& TO iResult1&
      CONTROL GET CLIENTtop/left location hDlg, id& TO wide&, high&
      CONTROL GET LOCtop/left location hDlg, id& TO x&, y&
      CONTROL GET SIZEwidth/height hDlg, id& TO width&, height&
      CONTROL GET TEXTtext hDlg, id& TO txt$
      CONTROL GET USERget user data hDlg, id&, index& TO retvar&
      CONTROL HANDLE window handle for control id hDlg, id& TO hCtl&
      CONTROL KILLremove control hDlg, id&
      CONTROL POSTput message in queue (non-blocking) hDlg, id&, Msg&, wParam&, lParam&
      CONTROL REDRAWschedule redraw of control hDlg, id&
      CONTROL SENDsend message to control, wait for processing hDlg, id&, Msg&, wParam&, lParam& TO iResult2&
      CONTROL SET CHECKset check for 3state or checkbox hDlg, id&, checkstate&
      CONTROL SET CLIENTchange size to specific client area size hDlg, id&, wide&, high&
      CONTROL SET COLORset fg/bg color hDlg, id&, fgcolor&, bgcolor&
      CONTROL SET FOCUSset focus hDlg, id&
      CONTROL SET FONTselect font for a control hDlg, id&, fonthandle&
      CONTROL SET LOCrelocate control within dialog hDlg, id&, x&, y&
      CONTROL SET OPTIONset check state of option control hDlg, id&, minid&, maxid&
      CONTROL SET SIZEchange control size hDlg, id&, width&, height&
      CONTROL SET TEXTchange control text hDlg, id&, text$
      CONTROL SET USERset user data hDlg, id&, index&, uservalue&
      CONTROL SHOW STATE     toggle visibility hDlg, id&, showstate& TO iResult3&

    If you have any suggestions or corrections, please let me know.