An Introduction to Controls

1
An Introduction to Controls

• Rainer Becker
• dFPUG / ISYS GmbH
• Germany

2
About the Speaker

• German FoxPro User Group
• ISYS GmbH
• MS Solution Provider
• MS Consulting Services
• Adress Rainer Becker, Messerschmittstr. 2a,
• 65760 Eschborn, Germany
• Phone [phone], Fax -65997
• CompuServe 100024,1364 / GO MSCESYS

3
Whats included

• Short Introduction to principles of
• Properties/Events/Methods
• Guided Tour through all Controls
• - walking all properties upstairs
• Some words about
• Containers, Naming, Builders

4
Whats excluded

• Form Designer
• Class Designer
• Grid-Control
• OLE-Controls
• (but you might get a good base for all of that)

• Classes
• Inheritance
• Non-Visual Objects
• Event-Model

5
Form Designer
Toolbars

• Properties
• Data
• Method
• Layout
• Other

• Controls
• Libs
• Locks

• Layout
• Palette

• Design

6
Vocabulary

• What are Properties ?
• What are Methods ?
• What are Events ?
• How to avoid confusion?
• How to reference objects ?

7
What are PROPERTIES?

• Think of them as bound variables
• Public vars with a private path
• Example COMMENT, HEIGHT
• Add your own!
• Later on you will need them - especially
• for non-visual objects or even applications

8
What are METHODS?

• Think of them as old-style snippets
• Procedures bound to Controls/Forms
• Example Refresh, SetFocus
• Add your own!
• You will sometimes need them
• - but building your own is real fun!

9
What are EVENTS?

• Think of them as old-style snippets
• Procedures bound to Windows-Events
• Example old-fashioned VALID, CLICK
• You can not extend!
• Events are methods bound to OS/VFP/USER
• You normally need only some of them
• - but it is great that there are so many!

10
Avoid Confusion

• Events and Methods have a Procedure
• Events could be seen as an Event Method
• Some Properties are followed by actions
• These Categories are not closed boxes
• There are many - but most are easy to use!
• Obey Graphical hints
• Bold changed, Italic read-only
• Use RESET TO DEFAULT (right mouse button)

11
Syntax

• objectvariable.form.control.property Setting
• THIS.
• THISFORM.
• THISFORMSET.
• _SCREEN.
• WITH.. ..ENDWITH, COUNT / PAGES

• ACTIVEFORM.
• ACTIVEPAGE.
• ACTIVECONTROL.
• PARENT.

12
Controls - A Guided Tour

• Timers
• Lines
• Shapes
• Images
• Labels
• Command Buttons
• Option Buttons
• Check Boxes
• Text Boxes

• Edit Boxes
• Spinners
• Combo Boxes
• List Boxes
• Option Groups
• Command Groups
• Page Frames
• Grids
• OLE-Controls

13
Not all of them are new! Renamed
Controls

• Text gt Label control
• GET-Field gt Text box
• Edit Region gt Edit box
• Popup gt Combo box
• Radio button gt Optionb.
• Push button gt Command
• Screen(Set) gt Form (Set)
• Picture gt Image

• Really new are
• Timers
• Page
• Grid
• OCX
• Nearly all are enhanced!

14
Lets start with a new but small one
Timers

• Data
• Methods
• Layout
• Other
• Tips

Comment, Tag BASIC, TimerEvent,
Reset COORDINATES CLASS, Interval - Not executed
while Menu open - Not exact enough for RealTime
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Timer Basic Data/Layout

• Timer (one of each)
• TimerEvent Procedure called at Event
• ResetMethod Restart timer
• IntervalProp. Timer in milliseconds
• Data
• Comment You should use it!
• Tag Free property
• Layout
• Top, Left, Heigth, Width

16
Basic Other

• Other
• Name Naming conventions
• Enabled logical Flag
• Class Objects belong to classes
• ClassLibrary optional VCX of the class
• Baseclass Base class derived from
• Parentclass optional derived from
• Parent runtime container object

17
Basic Events/Methods

• Events
• Init Object initialised
• Destroy Object removed
• Error local error-handler
• Methods
• CloneObject runtime duplication
• SaveAsClass objects from VCX to VCX
• Read/WriteExpression/Method at design time

18
Lines

• Data
• Events
• Methods
• Layout
• Other
• Tips

--- CLICK, MOUSE, DRAG Drag, Move, UIEnable,
ZOrder DragIcon/Mode, BORDER,Draw- Mode,
MousePointer, LineSlant HelpContextID - No
3D-line-effects
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Click Mouse EventsVisible Objects

• Click
• Click Mouse left click
• DblClick Mouse double click
• RightClick Mouse right click
• Mouse
• MouseMove Mouse over object
• MouseDown Mouse pressed for click
• MouseUp Mouse released
• MousePointer 12 pointer versions

20
Drag Drop Visible Objects

• Drag
• DragDrop End of drag, target event
• DragOver object over target, target event
• Methods
• Drag Method for manual dragging
• Move Method for manual moving
• Properties
• DragIcon Cursor Icon for drag
• DragMode automatic / manual

21
Properties Visible Objects

• Bordercolor, -style, -width for border
• Visible Temporary hide object
• HelpContextID for HelpCompiler
• ZOrder Meth. active Page, tlb order
• UIEnable Evt. Page activate event
• Drawmode 16 different modes
• (Line/Shape/Form)
• LineSlant special line property

22
Shapes
--- --- BackColor/Style, FillColor/Style, ColorSch
eme/Source, ToolTip SpecialEffect,
Curvature --- - Shapes in front block the click
event

• Data
• Methods
• Layout
• Other
• Tips

23
Properties Plain Objects

• Colors
• BackStyle Transparent / Opaque (Default)
• BackColor RGB-Color for Qpaque objects
• FillColorStyle Transparent, Solid, Lines
• FillColor RGB-Color if not transparent
• ColorScheme Object/Form/Source/Default
• ColorSource Scheme for AboveSource
• ToolTipText ToolTip if Form.ShowTips.T.
• SpecialEffect Plain or 3D
• Curvature 0rectangle - 99circle

24
Images

• Data
• Methods
• Layout
• Other
• Tips

--- --- Picture (Bitmap, Icon) Stretch
(Clip/Isometric/Stretch) --- - Stretch also used
for OLE
25
Labels

• Data
• Methods
• Layout
• Other
• Tips

--- --- Caption, FONT, COLOR AutoSize, WordWrap,
Alignment --- - The Caption can be a function
26
Layout PropertiesObjects with Caption

• FontName FontSize
• FontFlags FontBold, FontItalic,
  FontStrikeThru,
• FontOutline,
  FontUnderline, FontShadow
• Color DisabledBackColor,
  (Disabled)ForeColor
• Caption Text to be shown (function)
• Alignment Left/Right/Centered
• AutoSize Resize horiz. for text
• WordWrap Wrap words/resize vertical

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Command Buttons

• Data
• Methods
• Layout
• Other
• Tips

TerminateRead ErrorMessage, see
EVENTS DownPicture, DisabledPicture StatusBarText,
(StyleInv.) TabIndex, TabStop (Forms!)
Default, Cancel (not \! or \? ) - Use small
fonts with pictures - Use StatusBarText instead
28
Eventsfor accessible objects

• When old-fashioned WHEN
• Valid old-fashioned VALID
• GotFocus Tabbed to it
• LostFocus Tabbed somewhere else...
• SetFocus Method (enabled visible)
• KeyPress Key Preview Event !
• Refresh SHOW GET (Requery,Page)
• Message Return Message text (Old!)

29
Option Buttons

• Data
• Methods
• Layout
• Other
• Tips

ControlSource Field or memvar Value same type as
the --- ControlSource Alignment (Left/Right)
for button SpecialEffect not for command
button --- - Only in Option Button Groups!
30
Avoid Confusion

• Name object name
• Caption title
• ControlSource differs
• memvar
• field
• function
• Value object value

31
Check Boxes

• Data
• Methods
• Layout
• Other
• Tips

--- InteractiveChangeEvent ProgrammaticChangeEvent
--- --- - ProgrammaticChange important!
32
Text Boxes

• Data
• Methods
• Layout
• Other
• Tips

Format, InputMask, Margin, Read- Only,
Open/MemoWindow RangeHigh, RangeLow SELECT, Style
(SAY-compatible), PasswordChar HideSelection -
Play with selected areas!
33
Selected Text

• SelStart Begin of selection
• SelLength Number of chars
• SelText Complete Selected text
• HideSelection Show after LostFocus
• SelectedForeColor Text color
• SelectedBackColor Background color

34
Edit Boxes

• Data
• Methods
• Layout
• Other
• Tips

MaxLength --- ScrollBars (vert.
horiz.) AllowTabs - Selected text applies here
35
Spinners

• Data
• Methods
• Layout
• Other
• Tips

KeyboardHigh/LowValue, Spin- nerHigh/LowValue,
Increment UpEvent, DownEvent --- --- - Use
High/LowValues instead of RangeEvents
36
Combo Boxes

• Data
• Methods
• Layout
• Other
• Tips

BoundColumn, DisplayValue AddItem,
AddListItem, ColumnCount, -Lines,
-Width Disabled/Select/Item/Back/ForeC TopIndex,
TopItemID, NEW IncrementalSearch,
Listcount, ListIndex, ListIdemID
37
LayoutCombo box

• ColumnCount Number of Columns
• ColumnLines Show column lines
• ColumnWidth Width of columns (colon-delimite
  d)
• ItemBack/ForeColor
• SelectedItemBack/ForeColor
• DisabledItemBack/ForeColor

38
DataCombo box

• RowSourceType 9 options
• RowSource name type
• BoundColumn Column bound to Value
• DisplayValue Text or pos. for display
• ItemData Additional value
• List Array of text
• Sorted Alphabetically sorted
• FirstElement, NumberOfElements for Arrays

39
Methods OtherCombo box

• Methods
• Requery Requery SQL/QPR-Source
• Other
• IncrementalSearch self-explanatory
• TopIndex first visible item
• NewIndex last AddItem-position
• Listcount Number of items
• ListIndex (Last) selected item

40
What are IDs?Combo box

• ItemIDData Additional value by ID
• ListItem Array of text by ID
• Other
• TopItemID ID of topmost vis. list-item
• NewItemID last AddItem-ID
• ListItemID (Last) selected item ID
• ( List ListItem / ListIndex ListItemID)
• ( RowSourceType (0None), (1Value) )

41
ID-MethodsCombo box

• AddItem Add at position
• AddListItem Add with ID
• RemoveItem Remove from position
• RemoveListItem Remove with ID
• Clear Delete all items
• IndexToItemID Position -gt ID
• ItemIDToIndex ID -gt Position

42
List Boxes

• Data
• Methods
• Layout
• Other
• Tips

--- --- --- MultiSelect - Use DisplayValue and
Value together for text and offset
43
Container
Hierarchy

• FrameSet
• Frame
• PageFrame
• Page
• Grid
• Column
• Option Group
• Command Group

• Frame
• PageF,Grid,Controls
• Page
• Grid, Controls
• Column
• Header, Controls
• Option Buttons
• Command Buttons

44
Option/Command Button Groups
--- AddObject, RemoveObject ButtonCount Buttons -
ChangeEvents only in Groups - No Inheritance for
new buttons

• Data
• Methods
• Layout
• Other
• Tips

45
Page Frames

• Data
• Methods
• Layout
• Other
• Tips

ActivePage --- PageCount, PageHeight/Width, Tabs,
TabStretch Pages (Array) -Drop objects on top
for all pages
46
Pages

• Data
• Methods
• Layout
• Other
• Tips

Controls (Array) --- ControlCount PageOrder,
KeyPreview - Reference all with PAGES.
47
Grids

• See Using the Grid Control - Whil Hentzen

48
OLE-Controls

• OLE Bound Controls
• "bound" to Genearl-fields
• no own Events
• OLE Container Controls
• OCX with own Events
• OLE unbound to fields
• See OLE Custom Controls - Steven Black

PicClip, Outline, Word 6.0, O-Gramm, Graph,
Excel, Comm, ClipArt, PowerPoint, Formula Editor
49
Container-Confusion

• Container Objects
• FrameSet, Frame, PageFrame, Page, Grid,
• Column, Option Group, Command Group
• Control Objects
• protected
• Custom Objects
• non-visual

50
Naming Conventions

• chk Check box
• cbo Combo box
• cmd Command
• cmg Com. group
• cnt Container
• ctl Control
• (cus Custom)
• edt Edit box
• frm Form
• frs Form set

• grd Grid
• grc Grid column
• grh Grid header
• img Image
• lbl Label
• lin Line
• lst List box
• olb OLE-bound
• ole OLE
• opt Option button

• opg Option group
• (otl Outline)
• pag Page
• pgf Page Frame
• sep Separator
• shp Shape
• spn Spinner
• txt Text box
• tmr Timer
• tbr Toolbar

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Ease your work!
Builders

• Textbox
• Editbox
• Listbox
• Combo-Box
• Option Group
• Command Group
• Grid

• Design-Only Methods
• - Read/Write-Method
• - Read/Write-Expression
• ASelObj( )
• You will love them!

52
Where to go from here? Related Sessions

• The Form Designer - Alan Schwartz
• Advanced Visual FoxPro Controls - Ted Roche
• Using the Grid Control in the Real World - Whil
  Hentzen
• OLE Custom Controls in Visual FoxPro - Steven
  Black
• Builders in Visual FoxPro - Steven Black
• Using Visual FoxPro Classes - Ken Levy
• ( The Class Browser - Ken Levy )
• ( Building applications using class libraries -T.
  M. T.-F. )

53
Questions?

• Check the VFP-sample files!
• RichTextFormat-Manuals...
• (or better click through the really big
  help-file)

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