draging a label without using mouse_move

[ZanM]

ok I'm making a paint type app so I get to know line, circle, and so on but I have a wierd problem

here is the form(I'm going to just past in the form as read by notepad, you copy paste to *.txt vb will create a form when you add the *.txt file (if it formats right in here))if you loud it run with it a start up form and try draw text you'll see what i mean
the main code foor draw text is in the form mdown & mUp and the timer tmrText

start from version
sel all the way to bottom

thanks

VERSION 5.00
Begin VB.Form frmDraw
AutoRedraw = -1 'True
BorderStyle = 1 'Fixed Single
Caption = "Draw"
ClientHeight = 5775
ClientLeft = 150
ClientTop = 720
ClientWidth = 7695
LinkTopic = "Form1"
MaxButton = 0 'False
ScaleHeight = 5775
ScaleWidth = 7695
StartUpPosition = 3 'Windows Default
Begin VB.Timer tmrtext
Interval = 1
Left = 7080
Top = 5280
End
Begin VB.Label lblDrawText
BackStyle = 0 'Transparent
Height = 255
Left = 7440
TabIndex = 0
Top = 5520
Visible = 0 'False
Width = 255
End
Begin VB.Menu mnuFIle
Caption = "&File"
End
Begin VB.Menu mnuEdit
Caption = "&Edit"
End
Begin VB.Menu mnuDraw
Caption = "&Draw"
Begin VB.Menu mnuDrawBox
Caption = "Draw &Box"
End
Begin VB.Menu mnuDrawCircle
Caption = "Draw &Circle"
End
Begin VB.Menu mnuDrawLine
Caption = "Draw &Line"
End
Begin VB.Menu mnuDrawText
Caption = "Draw &Text"
End
End
End
Attribute VB_Name = "frmDraw"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit

Dim Shape As String
Dim XStart, YStart As Single
Dim XPrevious, YPrevious As Single
Dim PrintText As Boolean

Private Declare Function SetCursorPos Lib "user32.dll" (ByVal x As Long, ByVal y As Long) As Long
Private Declare Function GetCursorPos Lib "user32.dll" (lpPoint As POINT_API) As Long

Private Type POINT_API
x As Long
y As Long
End Type
Private Sub Form_Load()
PrintText = False
End Sub

Private Sub Form_MouseDown(Button As Integer, Shift As Integer, x As Single, y As Single)
If Button = 1 Then
XStart = x
YStart = y
XPrevious = XStart
YPrevious = YStart
Me.DrawMode = 7
Me.DrawStyle = 1
Select Case Shape$
Case "Line"
Me.MousePointer = 2
Case "Circle"
Me.MousePointer = 2
Case "Box"
Me.MousePointer = 2
Case "Text"
If PrintText Then
Dim DrawString As String
Dim lX, lY
Dim lX2, lY2 As Single
Dim point As POINT_API
GetCursorPos point
lX = point.x
lY = point.y
lX2 = x
lY2 = y
DrawString = InputBox("Enter Text")
If DrawString = "" Then
Shape = ""
Me.MousePointer = 0
Exit Sub
End If
SetCursorPos lX, lY
lblDrawText.Caption = DrawString
lblDrawText.Width = TextWidth(DrawString)
PrintText = False
Me.MousePointer = 3
With lblDrawText
.ForeColor = Me.ForeColor
.Visible = True
.Left = lX / Me.Left
.Top = lY / Me.Top
tmrtext.Enabled = True
End With
Else
tmrtext.Enabled = False
Me.CurrentX = x
Me.CurrentY = y
Me.Print lblDrawText.Caption
lblDrawText.Visible = False
Me.MousePointer = 0
Shape = ""
Exit Sub
End If
End Select
End If
End Sub


Private Sub Form_MouseMove(Button As Integer, Shift As Integer, x As Single, y As Single)
Select Case Shape$
Case "Line"
Me.MousePointer = 2
Case "Circle"
Me.MousePointer = 2
Case "Box"
Me.MousePointer = 2
Case "Text"
Me.MousePointer = 3
End Select
If Button = 1 Then
Me.DrawMode = 10 'enable dotted line
Select Case Shape$
Case "Line"
Me.Line (XStart, YStart)-(XPrevious, YPrevious)
Me.Line (XStart, YStart)-(x, y)
Me.MousePointer = 2
Case "Circle"
Me.Circle (XStart, YStart), Sqr((XPrevious - XStart) ^ 2 + (YPrevious - YStart) ^ 2)
Me.Circle (XStart, YStart), Sqr((x - XStart) ^ 2 + (y - YStart) ^ 2)
Me.MousePointer = 2
Case "Box"
Me.Line (XStart, YStart)-(XPrevious, YPrevious), , B
Me.Line (XStart, YStart)-(x, y), , B
Me.MousePointer = 2
Case "Text"
'lblDrawText.Left = x
'lblDrawText.Top = y
'Me.MousePointer = 3
End Select
XPrevious = x
YPrevious = y
End If
End Sub


Private Sub Form_MouseUp(Button As Integer, Shift As Integer, x As Single, y As Single)
If Button = 1 Then
Me.DrawMode = 13
Me.DrawStyle = 0
Select Case Shape$
Case "Line"
Me.Line (XStart, YStart)-(x, y)
Me.MousePointer = 0
Shape = ""
Case "Circle"
Me.Circle (XStart, YStart), Sqr((x - XStart) ^ 2 + (y - YStart) ^ 2)
Me.MousePointer = 0
Shape = ""
Case "Box"
Me.Line (XStart, YStart)-(x, y), , B
Me.MousePointer = 0
Shape = ""
Case "Text"
End Select
End If
End Sub


Private Sub mnuDrawBox_Click()
Shape = "Box"
End Sub


Private Sub mnuDrawCircle_Click()
Shape = "Circle"
End Sub


Private Sub mnuDrawLine_Click()
Shape = "Line"
End Sub


Private Sub mnuDrawText_Click()
Shape = "Text"
' Dim DrawString As String
' DrawString = InputBox("Enter Text")
' lblDrawText.Caption = DrawString
' lblDrawText.Width = TextWidth(DrawString)
PrintText = True
End Sub


Private Sub tmrtext_Timer()
Dim lX, lY
Dim point As POINT_API
GetCursorPos point
lX = ScaleX(point.x, vbPixels, Me.ScaleMode)
lY = ScaleY(point.y, vbPixels, Me.ScaleMode)
' Screen.TwipsPerPixelY
lblDrawText.Left = lX 'ScaleX(lX, vbPixels, Me.ScaleMode) - ScaleX(Screen.TwipsPerPixelX, vbPixels, Me.ScaleMode)
lblDrawText.Top = lY 'ScaleY(lY, vbPixels, Me.ScaleMode) - ScaleY(Screen.TwipsPerPixelY, vbPixels, Me.ScaleMode)
End Sub

[Joacim Andersson]

I've changed your timer event slightly:

Private Sub tmrtext_Timer()
    Dim lX, lY
    Dim point As POINT_API
    Dim iDiffX%, iDiffY%
    
    iDiffX = Me.Width - Me.ScaleWidth - 5 * Screen.TwipsPerPixelX
    iDiffY = Me.Height - Me.ScaleHeight
    GetCursorPos point
    lX = ScaleX(point.x, vbPixels, Me.ScaleMode)
    lY = ScaleY(point.y, vbPixels, Me.ScaleMode)
    ' Screen.TwipsPerPixelY
    lblDrawText.Left = lX - Me.Left - iDiffX 
    lblDrawText.Top = lY - Me.Top - iDiffY
End Sub

The problem is that with GetCursorPos you get the mouse position counted from the upper left position of the screen and that may not be where your form is positioned.

Good luck!

[Edited by Joacim Andersson on 08-04-2000 at 04:01 AM]

[ZanM]

That did it. Where did you learn about the screen object and it relation to forms? The books I have are so vage about every thing they cover.... maybe you could recamend a good one....



Thanks

[ZanM]

I'm reading the change and not quite sure why it works. Could you explain it to me?



Thanks agian

[Joacim Andersson]

Well, there's a lot of good books out there. Some that I like is the "In a nutshell" series from O'Reilly.
Have a look at http://www.oreilly.com
They are "no nonsens just give me the facts" kind of books.

[Joacim Andersson]

The GetCursorPos gets the cursor position related to the screen and not to your form.
Lets say that your form Top position is at 1000 twips that would imply that you have to subtract 1000 twips from the point.y position that you get from the call to GetCursorPos so you get the right position within your form.

The problem is that your Labels top position is countet from the top of the inner border of your form and not from the very top position. You have to redraw your forms height of the title- and menu bar as well.

This would be the form height minus the form scaleheight. And that's what you store in the iDiffY variable.

In the iDiffX I added 5 extra pixels otherwise the label would have been just under the cursor and when you make a mouse click the mouse_down and mouse_up events would have been passed to your label and not your form.

I hope this clarifies things for you.

Best regards

[ZanM]

Thanks