How To Create a Thermometer Bar in Visual FoxPro

• Microsoft Visual FoxPro for Windows, versions 3.0, 5.0

SUMMARY

Windows-based applications often use a thermometer bar to represent the progress of a certain task visually. This article shows by example how to create a general-purpose thermometer bar that you can use in new or existing Visual FoxPro applications.

MORE INFORMATION

For this example, a timer is used to simulate a process. At regular intervals, the thermometer bar is updated to indicate the percentage of completion.

Step-by-Step Example

1. Create a new program that contains the following code:

   PUBLIC othermometer othermometer = CreateObject('thermometer') othermometer.Visible = .T.

   DEFINE CLASS thermometer AS form

              Height = 73
              Width = 385
              DoCreate = .T.
              AutoCenter = .T.
              Caption = ""
              Closable = .F.
              ControlBox = .F.
              MaxButton = .F.
              MinButton = .F.
              Movable = .F.
              Name = "Form1"
   
          ADD OBJECT shape2 AS shape WITH ;
              Height = 25, ;
              Left = 24, ;
              Top = 24, ;
              Width = 336, ;
              Name = "Shape2"
   
          ADD OBJECT shape1 AS shape WITH ;
              BackColor = RGB(0,0,255), ;
              Height = 25, ;
              Left = 24, ;
              Top = 24, ;
              Width = 0, ;
              Name = "Shape1"
   
          ADD OBJECT timer1 AS timer WITH ;
              Top = 0, ;
              Left = 0, ;
              Height = 23, ;
              Width = 23, ;
              Interval = 100, ;
              Name = "Timer1"
   
          PROCEDURE timer1.Timer
              IF This.Parent.shape1.Width<336
                 This.Parent.shape1.Width=This.Parent.shape1.Width+2
              ELSE
                 WAIT WINDOW 'Finished!'
                 Thisform.Release
              ENDIF
          ENDPROC
   
      ENDDEFINE
   
   

2. Run the program. The thermometer bar form should display, and the thermometer bar should progress at a constant rate until it finishes.

Another Example

The previous example uses a timer to simulate a process. This example demonstrates how to implement this thermometer bar in a loop. The WAIT TIMEOUT command inside the loop represents where the developer would place code appropriate for the application.

The overall width of the thermometer bar is 300 pixels. Because the code in the loop is executed 100 times, the width of the thermometer is incremented 3 pixels at a time to achieve an overall thermometer bar width of 300 pixels. This incremental value will vary depending on the number of times through the loop.

   PUBLIC othermometer
   othermometer = CreateObject('thermometer')
   othermometer.Visible = .T.

   i=0
   SET CONSOLE OFF

   DO WHILE i<100
      WAIT TIMEOUT 1        && Place application-specific code here
      othermometer.update()
      i=i+1
   ENDDO

   WAIT WINDOW 'Finished'

   othermometer.Release

   DEFINE CLASS thermometer AS form

           Height = 73
           Width = 349
           DoCreate = .T.
           AutoCenter = .T.
           Caption = ""
           Closable = .F.
           ControlBox = .F.
           MaxButton = .F.
           MinButton = .F.
           Movable = .F.
           Name = "Form1"

       ADD OBJECT shape2 AS shape WITH ;
           Height = 25, ;
           Left = 24, ;
           Top = 24, ;
           Width = 300, ;
           Name = "Shape2"

       ADD OBJECT shape1 AS shape WITH ;
           BackColor = RGB(0,0,255), ;
           Height = 25, ;
           Left = 24, ;
           Top = 24, ;
           Width = 0, ;
           Name = "Shape1"

       ADD OBJECT timer1 AS timer WITH ;
           Top = 0, ;
           Left = 0, ;
           Height = 23, ;
           Width = 23, ;
           Interval = 100, ;
           Name = "Timer1"

       PROCEDURE update
          This.shape1.Width=This.shape1.Width+3
       ENDPROC

   ENDDEFINE