Class

DesktopTextControl

Description

The base class for DesktopTextField and DesktopTextArea.

Methods

Name

Parameters

Returns

Shared

AcceptFileDrop

FileType As String

AcceptPictureDrop

AcceptRawDataDrop

Type As String

AcceptTextDrop

AddText

text As String

CharacterPosition

LineNumber As Integer

Integer

X As Integer, Y As Integer

Integer

Close

Copy

DrawInto

g As Graphics, x As Integer, y As Integer

InsertionPosition

X As Integer, Y As Integer

Integer

LineNumber

CharPosition As Integer

Integer

Paste

Refresh

immediately As Boolean = False

x As Integer, y As Integer, width As Integer, height As Integer, immediately As Boolean = False

SelectAll

SetFocus

Property descriptions

DesktopTextControl.Active

Active As Boolean

Indicates whether the control is active.

This property is read-only.

Active is False when the control's window is not in the foreground. When a DesktopWindow is deactivated, its controls are automatically deactivated unless AllowAutoDeactivate is set to False.

DesktopTextControl.AllowAutoDeactivate

AllowAutoDeactivate As Boolean

Determines whether the control should be deactivated (on macOS) when the parent window is deactivated. The default is True.

DesktopTextControl.AllowFocusRing

AllowFocusRing As Boolean

If True, the control indicates that it has the focus with a ring around its border; if False, the appearance of the control does not change when it has the focus.

This example is in the Initialized event of the control:

Me.AllowFocusRing = False

DesktopTextControl.AllowSpellChecking

AllowSpellChecking As Boolean

If True, words that are believed to be misspelled are underlined.

This example is in the Initialized event of a TextArea:

Me.AllowSpellChecking = True

DesktopTextControl.AllowTabs

AllowTabs As Boolean

If True, pressing the Tab key will enter a tab into the control instead of moving the focus to the next item in the tab order.

DesktopTextControl.AllowTabStop

AllowTabStop As Boolean

If True, the control is in the Tab Order and accepts the focus when the user tabs into it. The default is True. If False, the user cannot tab into it to give it the focus. However, the control can gain the focus by other means, such as the user's clicking on it or by setting the focus in code.

This example removes the control from the Tab Order:

Me.AllowTabStop = False

DesktopTextControl.BackgroundColor

BackgroundColor As ColorGroup

The background color for the control.

This code sets the value of the BackgroundColor property:

Me.BackgroundColor = Color.Red

DesktopTextControl.Bold

Bold As Boolean

If True, applies the bold style to the control's text.

This property is read-only.

Mac apps can only display font styles that are available. You cannot force a font to display in bold or italic if it does not have bold or italic variations available. In this situation, the Bold property will not affect the font.

This example sets the text to Bold.

Me.Bold = True

DesktopTextControl.Enabled

Enabled As Boolean

Determines if the control should be enabled when the owning window is opened.

A disabled control cannot be clicked and cannot receive the focus.

This example disables the control.

Me.Enabled = False

DesktopTextControl.FontName

FontName As String

Name of the font used to display the text content.

You can enter any font that is installed on the computer or the names of the two metafonts, "System" and "SmallSystem".

The System font is the font used by the system software as its default font. Different operating systems use different default fonts. If the system software supports both a large and small System font, you can also specify the "SmallSystem" font as your TextFont.

On macOS, "SmallSystem" specifies the OS's smaller system font and may make the control smaller in size as well. On Windows and Linux, "SmallSystem" is the same as "System".

This code sets the FontName property.

Me.FontName = "Helvetica"

DesktopTextControl.FontSize

FontSize As Single

Point size of the font used to display text content of a DesktopControl.

If you enter zero as the FontSize, your app will use the font size that works best for the platform on which it is running.

This code sets the font size to 16 points.

Me.FontSize = 16

DesktopTextControl.FontUnit

FontUnit As FontUnits

The units in which FontSize is measured.

See the FontUnits enumeration for valid values.

This example is in the Initialized event of the control. It sets the font unit to Pixel.

Me.FontUnit = FontUnits.Pixel

DesktopTextControl.Format

Format As String

Formats the contents of the control when it loses the focus.

It uses the same formatting conventions as the Format function. To turn off formatting, set the Format property to the empty string, "".

If you need to enforce an entry format rather than permitting any entry, use the Format property in conjunction with the Mask property. See the description of the ValidationMask property and the section "Masks" in the Notes section.

This line applies a dollar format when the user tabs out of the field.

Me.Format = "\$###,###.##"

DesktopTextControl.FormattedText

FormattedText As String

Returns the Text property formatted using the value in the Format property.

This property is read-only.

DesktopTextControl.Handle

Handle As Ptr

Returns a handle to the control.

This property is read-only.

For interfacing with Mac APIs using Declares, DesktopControl.Handle returns NSViews (except for DesktopToolbar).

On Windows returns the HWND of the control.

On Linux it returns a GtkWidget.

The following gets a handle to the control.

Var p As Ptr = Me.Handle

DesktopTextControl.HasBorder

HasBorder As Boolean

Indicates whether or not the border is visible.

DesktopTextControl.Height

Height As Integer

The height (in points) of the control.

This example sets the height of the control to 100:

Me.Height = 100

DesktopTextControl.HorizontalScrollPosition

HorizontalScrollPosition As Integer

Scrolls the text control horizontally to the position (in points) from the left edge of the control.

This code scrolls the control horizontally by 200 points.

TextArea1.HorizontalScrollPosition = 200

DesktopTextControl.Index

Index As Integer

If the control is used in a control set, this specifies the control's index in the set.

This property is read-only.

DesktopTextControl.Italic

Italic As Boolean

If True, applies the italic style to the control's text.

This property is read-only.

Mac apps can only display font styles that are available. You cannot force a font to display in bold or italic if it does not have bold or italic variations available. In this situation, the Italic property will not affect the font.

The following sets the Italic property for the control.

Me.Italic = True

DesktopTextControl.Left

Left As Integer

The distance from the left side of the control to the left side of its containing window or container.

The following example moves the control 100 points from the left side of the window:

Me.Left = 150

DesktopTextControl.LockBottom

LockBottom As Boolean

Determines whether the bottom edge of the control should stay at a set distance from the bottom edge of the parent control, if there is one, or the owning window.

This property can be set in the control's Inspector. The following example sets it in code.

Me.LockBottom = True

DesktopTextControl.LockLeft

LockLeft As Boolean

Determines whether the left edge of the control should stay at a set distance from the left edge of the parent control, if there is one, or the owning window.

LockLeft and Locktop default to True when you add a new control to a window. Existing controls will be altered only if LockRight and/or LockBottom are not set. LockLeft has no effect unless LockRight is True.

This property can be set in the control's Inspector. The following example sets it in code.

Me.LockLeft = True

DesktopTextControl.LockRight

LockRight As Boolean

Determines whether the right edge of the control should stay at a set distance from the right edge of the parent control, if there is one, or the owning window.

This property can be set in the control's Inspector. The following example sets it in code.

Me.LockRight = True

DesktopTextControl.LockTop

LockTop As Boolean

Determines whether the top edge of the control should stay at a set distance from the top edge of the parent control, if there is one, or the owning window.

LockTop and LockLeft default to True when you add a control to a window. Existing controls will be altered only if LockRight and/or LockBottom are not set. LockTop has no effect unless LockBottom is True.

This property can be set in the control's Inspector. The following example sets it in code.

Me.LockTop = True

DesktopTextControl.MouseCursor

MouseCursor As MouseCursor

The cursor to be displayed while the mouse is within the control and both the DesktopApplication and DesktopWindow class's MouseCursor properties are Nil.

If the DesktopApplication class's MouseCursor property is not Nil or the DesktopWindow's MouseCursor property is not Nil, then any control's MouseCursor property is ignored. You can use a cursor stored in the Cursors module. On Macintosh, you can also obtain a MouseCursor from a resource file.

This line in the Opening event of the control sets the default cursor to the finger pointer.

Me.MouseCursor = System.Cursors.FingerPointer

DesktopTextControl.Name

Name As String

The name of the control. Set the name of the control in the Inspector.

This property is read-only.

DesktopTextControl.PanelIndex

PanelIndex As Integer

If the control has been placed on a DesktopTabPanel or DesktopPagePanel control, this is the panel (page/tab) that the control is on. If the control is not on a panel, it returns -1.

The first panel is numbered zero. If the control has been placed on a panel of a DesktopTabPanel or DesktopPagePanel control, it returns the panel number. If the control is not on a DesktopPagePanel or DesktopTabPanel, it returns -1. If you change the PanelIndex to a nonexistent panel, the control will disappear until you give it a PanelIndex value that corresponds to a panel that exists.

If you are looking to change the currently selected panel (page/tab), use DesktopPagePanel.

This code displays the panel index of the control that is on the page.

MessageBox(Me.SelectedPanelIndex.ToString)

DesktopTextControl.Parent

Parent As Object

Used to get and set the control's parent control or window.

If the control is on the window, the Parent will be the Window. If the control is on the container, the Parent will be the container. If the control is completed enclosed by another control, the Parent will be that control.

If you do not want the enclosing control to be the parent, set the Parent property of that control to Nil to make it the Window.

If the parent control is somehow in another window, an InvalidParentException will occur.

The following example sets the parent of the control to the window.

Me.Parent = Nil

DesktopTextControl.ReadOnly

ReadOnly As Boolean

If True, the text of the control cannot be modified.

This example is in the Opening event of the control.

Me.ReadOnly = True

DesktopTextControl.Scope

Scope As Integer

Used to determine whether access to the control is Public (0) or Private (2). The default is Public.

This property is read-only.

Note

This is a designtime-only property and thus can only be set in the Inspector and is not accessible via code.

If the Scope of a control is set to Private, it cannot be accessed from outside its parent window.

DesktopTextControl.SelectedText

SelectedText As String

The currently selected text.

This example places the selected text from a DesktopTextArea into a DesktopTextField.

TextArea1.SelectionStart = 0
TextArea1.SelectonLength = 10

TextField1.Text = TextArea1.SelectedText

DesktopTextControl.SelectionLength

SelectionLength As Integer

The number of selected characters.

A SelectionLength of 0 means an insertion point rather than a selection. A value greater than the number of characters in the control means that the selection is from SelectionStart to the end of the control.

On Windows, selecting text via code does not display the text as selected unless the control has the focus. If you want this behavior, call SetFocus before setting the selection.

This example selects the first 10 characters of TextArea1.

TextArea1.SelectionStart = 0
TextArea1.SelectionLength = 10

DesktopTextControl.SelectionStart

SelectionStart As Integer

The position of the insertion point.

A value of zero means that the insertion point is before the first character. Use SelectionStart to set the position of the insertion point in the text. Use SelectionStart in conjunction with SelectionLength to select a portion of the text in the control, beginning with SelectionStart and extending for SelectionLength characters.

On Windows, selecting text via code does not display the text as selected unless the control has the focus. If you want this behavior, call SetFocus before setting the selection.

This example selects the first 10 characters of TextArea1.

TextArea1.SelectionStart = 0
TextArea1.SelectionLength = 10

DesktopTextControl.TabIndex

TabIndex As Integer

The control's position in the Tab Order. The control with whose TabIndex is 0 will get the focus first.

On macOS, only controls where you enter data from the keyboard typically get the focus. In order to manually set focus to controls that don't allow keyboard entry, go to System Preferences, click on the Keyboard icon then on the Shortcuts tab and then check the Use keyboard navigation to move focus between controls checkbox.

This example sets the control's TabIndex.

Me.TabIndex = 2

DesktopTextControl.Text

Text As String

The text displayed.

Assigning a string to the Text property replaces the entire contents of the control. The font, size, and color are uniform and match the values last set with the FontName, FontSize, and TextColor properties, or if these haven't been used, the settings in the IDE.

Please note that the implementation of the DesktopTextField and DesktopTextArea controls is platform dependent. Do not expect that the text you assign is the same as the text you receive from this property. For example on Mac your text is converted to UTF-8 internally. On Windows all text after a null character (which means chr(0) and not "0") is ignored. End of line characters can change to their platform specific counterpart. Special characters with Asc values below 32 may be ignored or removed.

Clear (remove) any text that is displayed in the TextArea:

TextArea1.Text = ""

This example places the selected text from a DesktopTextArea into a DesktopTextField.

TextArea1.SelectionStart = 0
TextArea1.SelectionLength = 10

TextField1.Text = TextArea1.SelectedText

DesktopTextControl.TextAlignment

TextAlignment As TextAlignments

Sets the paragraph alignment for entire contents of the control.

Use the TextAlignments enumeration to get/set the value of this property.

For the DesktopTextArea control, use the SelectionAlignment property to set paragraph alignments for individual paragraphs. Currently the Default alignment is the same as Left aligned. Setting the alignment on Linux requires GTK+ 2.4 or greater.

This example is in the Initialized event of the control.

Me.TextAlignment = TextAlignments.Center

DesktopTextControl.TextColor

TextColor As ColorGroup

Gets or sets the color of the text. The default value is black.

The following example sets the TextColor.

Me.TextColor = Color.Red

DesktopTextControl.Tooltip

Tooltip As String

Text of help message displayed as a Windows or Linux "tooltip" or macOS help tag.

The tip/tag is displayed when the user hovers the mouse cursor over the control.

This example adds a tooltip to a control:

Me.Tooltip = "Click to bark."

DesktopTextControl.Top

Top As Integer

The distance from the top of the control to the top of its containing window or container.

This example sets the top of the control to 140 points from the top of the window:

Me.Top = 140

DesktopTextControl.Transparent

Transparent As Boolean

Determines whether the control is transparent on Windows. The default is False. Has no effect on macOS or Linux.

Transparent controls draw more slowly and use more memory in order to cache the background. Unless you absolutely require transparency, leave this set to False.

For projects that were created prior to 2018r1, this property defaults to True to emulate previous behavior. Consider changing it to False to improve performance if you do not require transparency.

DesktopTextControl.Underline

Underline As Boolean

If True, applies the underline style to the control's text.

This property is read-only.

This code underlines the control's text or caption property.

Me.Underline = True

DesktopTextControl.ValidationMask

ValidationMask As String

Use the ValidationMask property to filter user input on a character-by-character basis and add formatting characters.

For example, a mask for a Telephone number field can add parentheses, spaces, and dashes as literals, that are used for formatting, and the digit mask symbol '#' to restrict entry to numbers only. It uses the same mask characters as Visual Basic. If the user enters a character that is prohibited by the mask, it causes the ValidationFailed event to occur.

You can use the ValidationMask property in conjunction with the Format property. The ValidationMask filters the entry, while the Format property applies a format to the entry. The formats are the same as for the Format function.

The DesktopTextField will autocomplete any literal mask characters for the user. If the user uses the Backspace key he/she can backup the autocompletion but only 1 character at a time.

To turn off the ValidationMask, set it to the empty string, "".

You can set the ValidationMask property in the Properties pane. If you use the "#" character as the first character of the mask, there is the remote possibility that it may be confused with the name of a constant. When you use a constant in the Properties pane, you precede its name with the "#" sign. If you want both a constant and a mask to be named "Example", then you should create a new constant named "poundExample" with its value set to "#Example" and assign that in the Properties pane.

The following table shows the characters that you can use to define a mask.

Mask Character

Description

#

The single digit placeholder. The user can type only a digit (numeric) character in this position. For example, the mask "(###) ###-####" accepts the entry 5551212121" and returns "(555) 121-2121".

.

Decimal placeholder.

,

Thousands separator.

:

Time separator.

/

Date separator.

Mask escape character.

&

Character or space placeholder. It accepts one character.

C

Character or space placeholder, where entry is optional. It operates like the '&' placeholder. For example, the mask "CCCC-CC" formats "1233ed" as "1233-ed".

>

Convert all the characters that follow to uppercase.

<

Convert all the characters that follow to lowercase.

A

Alphanumeric character placeholder, where entry is mandatory.

a

Alphanumeric character placeholder, where entry is optional.

0

The literal "0" (zero). For example, the mask "99.00" formats the entry "22" as "22.00". The mask "CC0-9999" accepts the entry "1234" and returns it as "CC0-1234". The mask "##,###.00" accepts the entry "12345" and returns "12,345.00". The mask "99.00" accepts "21" and returns "21.00".

9

A Single (numeric) digit, where entry is optional.

?

Alphabetic placeholder. Entry is optional. For example, the mask "???" accepts three alphabetic characters. It rejects numeric characters.

Any literal

All other symbols are displayed as literals for formatting purposes. For example, the mask "99[9]" accepts the entry "333" and returns "33[3]".

~

Reserved for future use. If you use "~" it will trigger an exception error. Use ~ instead.

Mask

Description

999,999.99

Formats 11122233 as "111,222.33" (Using the US thousands separator.)

99.00

Formats "22" as "22.00."

###-##-####

US Social Security number. Fomats "123456789" as 123-45-6789.

:

TextField1.ValidationMask = "###-##-####"
TextField1.ValidationMask = "(###) ###-####" ' US Phone number, with area code

If the user tries to enter a character that is prohibited by the mask, a ValidationFailed event occurs. The character that the user attempted to enter and the character position is passed to the ValidationFailed event, where you can handle the keystroke as you like.

To cancel the ValidationMask, set it to the empty string:

TextField1.ValidationMask = ""

DesktopTextControl.Visible

Visible As Boolean

Determines whether the control is visible when its owning window is opened. The default is True: the control is visible.

The following code makes the control invisible:

Me.Visible = False

DesktopTextControl.Width

Width As Integer

The width (in points) of the control.

The following example resizes the control:

Me.Width = 200

DesktopTextControl.Window

Window As DesktopWindow

The control's parent window.

This property is read-only.

This code gets the parent window's Title property.

MessageBox(Me.Window.Title)

Method descriptions

DesktopTextControl.AcceptFileDrop

AcceptFileDrop(FileType As String)

Permits documents of type FileType to be dropped on the control. FileType must be a file type that you defined in via the FileType class or the File Type Sets Editor.

This code in the Opening event makes it possible for the user to drop either a picture or a file that is a jpeg image. The File Type Sets editor was used to define the “image/jpeg” file type. It is one of the “Common File Types” that is available in the editor.

Me.AcceptPictureDrop
Me.AcceptFileDrop("image/jpeg")

To restrict file drops to just folders (and not files), you can put this code in the DragEnter event:

If Not obj.FolderItem.IsFolder Then Return True

DesktopTextControl.AcceptPictureDrop

AcceptPictureDrop

Permits pictures to be dropped on the control.

If a control should accept pictures in a drag and drop, then AcceptPictureDrop needs to be called prior to the drop. Typically, it is in the Opening event of the control itself. For example, the line:

Me.AcceptPictureDrop

in the Opening event of the control that will receive the dragged pictures is needed. When the picture is dropped, the DropObject event is called and this is where you will put your code to handle the drop.

Opening Event:

Me.AcceptPictureDrop

DropObject Event:

If obj.PictureAvailable Then
  Me.Backdrop = obj.Picture
End If

DesktopTextControl.AcceptRawDataDrop

AcceptRawDataDrop(Type As String)

Permits data (of the Type specified) to be dropped on the control.

The following specfies a generic file type defined in the File Type Sets editor.

Me.AcceptRawDataDrop("????")

DesktopTextControl.AcceptTextDrop

AcceptTextDrop

Permits text to be dropped on the control.

This line in the Opening event of a control that can accept dragged text.

Me.AcceptTextDrop

DesktopTextControl.AddText

AddText(text As String)

Adds the passed text to the current Text. Call AddText rather than using the + operator to add text to existing text.

This example reads a text field in blocks of 1000 characters using Read.

Var f As FolderItem
Var dlg As OpenDialog
Var t As TextInputStream

' create a new openDialog
dlg = New OpenFileDialog
' set what type of file it looks for
dlg.Filter = "text/plain"

' run the dialog
f = dlg.ShowModal

' check to make sure the user didn't click cancel
If f <> Nil Then
  Try
    t = TextInputStream.Open(f)
    ' Read all of the text, 1000 characters at a time
    ' into the TextField
    While Not t.EndOfFile
      myTextArea.AddText(t.Read(1000, Encodings.UTF8))
    Wend
    t.Close
  Catch error As IOException
    ' the file could not be a read as a text file
    MessageBox("The selected file is not a text file. Error: " + error.Message)
  End If
Else
  ' the user clicked cancel... just ignore it
End If

DesktopTextControl.CharacterPosition

CharacterPosition(LineNumber As Integer) As Integer

Returns as an Integer the character position for pixel coordinates X, Y relative to the control.

DesktopTextControl.CharacterPosition

CharacterPosition(X As Integer, Y As Integer) As Integer

Returns as an Integer the character position for pixel coordinates X, Y relative to the control.

Characters are numbered consecutively from the start until the end of the control. The first character is numbered 1. The first line is numbered zero.

This example gets the character position of the first character of the second line.

Var i As Integer
i = TextArea1.CharacterPosition(1)

This example is in the MouseDown event of the control. The event passes in the X,Y coordinates of the MouseDown event. The example gets the position of the character at the passed coordinates.

Var i As Integer
i = Me.CharacterPosition(x, y)
MessageBox(i.ToString)
Return True

DesktopTextControl.Close

Close

Closes a control.

Closing a control permanently removes the control from memory, making it impossible to access. You can close both non-indexed controls and indexed controls. When you close an indexed control, the indexes for the remaining controls will shift downward so that the indexes start with zero and are consecutive.

The following code closes the control. When this is executed from a visible control, the control disappears from the window.

Me.Close

DesktopTextControl.Copy

Copy

Copies the selected text in the TextArea to the Clipboard, including the styled text information.

This example copies the selected text and places it on the Clipboard.

TextArea1.SelectionStart = 0
TextArea1.SelectionLength = 10
TextArea1.Copy

DesktopTextControl.DrawInto

DrawInto(g As Graphics, x As Integer, y As Integer)

Draws the contents of the control into the specified Graphics context. The parameters x and y are the coordinates of the top, left corner.

Note

DrawInto will only work if the control is on a window or container.

This example draws the current control into the Graphics of a Picture and then displays it as the Backdrop of a Canvas:

Var p As New Picture(Me.Width, Me.Height)
Me.DrawInto(p.Graphics, 0, 0)
Canvas1.Backdrop = p

DesktopTextControl.InsertionPosition

InsertionPosition(X As Integer, Y As Integer) As Integer

Returns (as an Integer) returns the position of the insertion point closest to pixel coordinates X,Y relative to the control. The returned value is zero-based.

This example is in the MouseDown event of a DesktopTextArea. This event passes in the X,Y coordinates of the MouseDown event and the method returns the corresponding character position.

Var i As Integer
i = TextArea1.InsertionPosition(x, y)
MessageBox(i.ToString)
Return True

DesktopTextControl.LineNumber

LineNumber(CharPosition As Integer) As Integer

Returns (as an Integer) the line number in which the CharacterPosition character appears.

Characters are numbered consecutively with the first character numbered 1. The first line is numbered zero. Used with ScrollPosition, this lets you scroll the control to a particular place in the text.

The line number reflects line breaks from both hard line breaks in the text and soft line breaks caused by word-wrapping within the control.

Gets the line number for the character at position 100:

Var lineNum As Integer = TextArea1.LineNumber(100)

This example searches a TextArea using text provided in a TextField and then scrolls to the text in the TextArea:

Var searchText As String = TextField1.Text
Var position As Integer = TextArea1.Text.IndexOf(searchText)

If position > -1 Then
  TextArea1.VerticalScrollPosition = TextArea1.LineNumber(position)
Else
  ' IndexOf returns -1 if no match was found.
End If

DesktopTextControl.Paste

Paste

Pastes the styled or unstyled text on the Clipboard into the editing area at the insertion point, adding the text to the existing text.

When pasting into a DesktopTextArea, if the text is styled, the style information is preserved.

This example pastes the contents of the Clipboard into TextArea2 at the insertion point.

TextArea2.Paste

DesktopTextControl.Refresh

Refresh(immediately As Boolean = False)

Redraws the portion specified of the contents of the control the next time the OS redraws the control or immediately if True is passed.

If you are calling this so frequently that you experience a slowdown in your code, pass True for the immediately parameter.

Calling this method causes the Render event to fire.

Refresh the entire area immediately:

Me.Refresh(True)

DesktopTextControl.Refresh

Refresh(x As Integer, y As Integer, width As Integer, height As Integer, immediately As Boolean = False)

Redraws the portion specified of the contents of the control the next time the OS redraws the control or immediately if True is passed.

Refresh a portion of the area the next time the OS redraws the control:

Me.Refresh(100, 150, 200, 300)

DesktopTextControl.SelectAll

SelectAll

Selects all of the text in the control. If there is no text in the control, SelectAll does nothing.

This example selects all the text in the control.

TextArea1.SelectAll

DesktopTextControl.SetFocus

SetFocus

If applicable, sets the focus to the DesktopUIControl. KeyDown events are directed to the control.

If the control cannot get the focus on the platform on which the application is running, SetFocus does nothing. The SetFocus method of the DesktopWindow class or the ClearFocus method can be used to remove the focus from the control that currently has the focus, leaving no control with the focus.

Note

On the Mac you need Full Keyboard Access turned on in System Preferences (Keyboard->Shortcuts) in order to manually set focus to non-text controls.

The following example in the Opening event sets the focus to the that control. If another control has the focus when this line is executed, then the user sees this control gets the focus.

Me.SetFocus

Event descriptions

DesktopTextControl.Closing

Closing

The control is closing.

DesktopTextControl.ConstructContextualMenu

ConstructContextualMenu(Base As DesktopMenuItem, x As Integer, y As Integer) As Boolean

This event is called when it is appropriate to display a contextual menu for the control.

This event handler is the recommended way to handle contextual menus because this event figures out whether the user has requested the contextual menu, regardless of how they did it. Depending on platform, it might be in the MouseUp or MouseDown event and it might be a right+click or by pressing the contextual menu key on the keyboard, for example.

Base is analogous to the menu bar for the contextual menu. Any items you add to Base will be shown as menu items. If you return False, the event is passed up the parent hierarchy.

If you return True, the contextual menu is displayed. The parameters x and y are the mouse locations. If the event was fired because of a non-mouse event, then x and y are both set to -1. See the example of a contextual menu in the following section.

The following ConstructContextualMenu event handler builds a menu with three menu items plus a submenu with three additional menu items.

' Add some items
base.AddMenu(New DesktopMenuItem("Test 1"))
base.AddMenu(New DesktopMenuItem("Test 2"))
base.AddMenu(New DesktopMenuItem("Test 3"))

' Add a Separator
base.AddMenu(New DesktopMenuItem(DesktopMenuItem.TextSeparator))

' Add a sub menu
Var submenu As New DesktopMenuItem("SubMenu")
submenu.AddMenu(New DesktopMenuItem("SubMenu Test 1"))
submenu.AddMenu(New DesktopMenuItem("SubMenu Test 2"))
submenu.AddMenu(New DesktopMenuItem("SubMenu Test 3"))
base.AddMenu(submenu)

' Add a Separator
base.AddMenu(New DesktopMenuItem(DesktopMenuItem.TextSeparator))

Return True

DesktopTextControl.ContextualMenuItemSelected

ContextualMenuItemSelected(HitItem As DesktopMenuItem) As Boolean

Fires when a contextual menuitem selectedItem was selected but the MenuItemSelected event and the MenuHandler for the DesktopMenuItem did not handle the menu selection.

This event gives you a chance to handle the menu selection by inspecting the menuitem's Text or Tag properties to see which item was selected. Use this in conjunction with ConstructContextualMenu if you have not specified the MenuItemSelected event or the Menu Handler for the items on the contextual menu. See the example of a contextual menu in the examples for the DesktopUIControl class.

Return True if this event has handled the item the user chose from the contextual menu. Returning False will cause the control's parent to execute its ContextualMenuItemSelected event. This can be handy if you have the same contextual menu for several controls who share the same Parent (several on the same window for example). By returning False you can handle them all in a single event.

This simple event handler displays the value of the selected menu item.

If selectedItem <> Nil Then MessageBox(selectedItem.Text)
Return True

DesktopTextControl.DragEnter

DragEnter(obj As DragItem, Action As DragItem.Types) As Boolean

Fires when the passed DragItem enters the DesktopUIControl.

Returns a Boolean. Return True from this event to prevent the drop from occurring.

The Action parameter specifies the type of drag action.

To restrict file drops to just folders (and not files), you can put this code in the DragEnter event:

If Not obj.FolderItem.IsFolder Then Return True

DesktopTextControl.DragExit

DragExit(obj As DragItem, Action As DragItem.Types)

Fires when the passed DragItem exits the DesktopUIControl.

The Obj parameter is the item being dragged. The Action parameter specifies the type of drag action.

DesktopTextControl.DragOver

DragOver(x As Integer, y As Integer, obj As DragItem, Action As DragItem.Types) As Boolean

Fires when the DragItem is over the DesktopUIControl.

The Obj parameter is the object being dragged. The coordinates x and y are relative to the DesktopUIControl. Returns a Boolean. Return True from this event to prevent the drop from occurring.

The Action parameter specifies the type of drag action, which is typically done by holding down a modifier key (Shift, Alt, Option, Command, etc.) while doing the drag.

DesktopTextControl.DropObject

DropObject(Obj As DragItem Action As DragItem.Types)

The item represented by Obj has been dropped on the control.

The Obj parameter is the object being dragged. The Action parameter specifies the type of drag action.

The following DropObject event handler can handle either a dropped picture or a dropped file. The type of file that it can handle needs to have been specified in a call to AcceptFileDrop prior to the drop, for example, in the Opening event.

If Obj.PictureAvailable Then
  Me.Image = obj.Picture
ElseIf Obj.FolderItemAvailable Then
  Me.Image = Picture.Open(obj.FolderItem)
End If

DesktopTextControl.FocusLost

FocusLost

The control has lost the focus.

Note

On macOS, controls other than text fields and lists will accept and lose focus only if the full keyboard access option is enabled in System Preferences/Keyboard.

DesktopTextControl.FocusReceived

FocusReceived

The control has received the focus and has a selection rectangle around it.

Note

On macOS, controls other than text fields and lists will accept focus only if the full keyboard access option is enabled in System Preferences/Keyboard.

DesktopTextControl.KeyDown

KeyDown(Key As String) As Boolean

The user has pressed the Key passed while the control has the focus.

How KeyDown works depends on the type of control.

Returning True means the key is intercepted, preventing the key from actually reaching the control at all. This would be useful if you want to override the behavior of the tab key for example. Returning False means the key reaches the control.

DesktopTextControl.KeyUp

KeyUp(Key As String)

Fires when the passed Key is released in the control that has the focus.

It is not guaranteed to be the same key that received the KeyDown event.

DesktopTextControl.MenuBarSelected

MenuBarSelected

Indicates that the control has the focus and a menu (not a menu item) has been selected by the user.

DesktopTextControl.MouseDown

MouseDown(X As Integer, Y As Integer) As Boolean

The mouse button was pressed inside the control's region at the location passed in to x, y.

This event fires repeatedly while the mouse button is being held down.

The coordinates x and y are local to the control, i.e. they represent the position of the mouse click relative to the upper-left corner or the control.

Return True if you are going to handle the MouseDown. In such a case:

  • The Pressed event, if any, will not execute and the state of the object will not change.

  • You will receive the MouseUp event.

If you return False, the system handles the MouseDown so the MouseUp event handler do not get called.

The MouseDown event uses the DragItem constructor when the user drags the contents of the control. It is:

Var d As DragItem
d = New DragItem(Self, Me.Left, Me.Top, Me.Width, Me.Height)
d.Picture = Me.Image
d.Drag ' Allow the drag

DesktopTextControl.MouseDrag

MouseDrag(X As Integer, Y As Integer)

The mouse button was pressed inside the control and moved (dragged) at the location local to the control passed in to x, y.

This event fires repeatedly while the mouse button is down regardless of whether or not the mouse coordinates are changing.

This event will not occur unless you return True in the MouseDown event.

DesktopTextControl.MouseEnter

MouseEnter

The mouse has entered the area of the control.

DesktopTextControl.MouseExit

MouseExit

The mouse has left the area of the control.

DesktopTextControl.MouseMove

MouseMove(X As Integer, Y As Integer)

The mouse has moved within the control to the coordinates passed. The coordinates are local to the control, not to the window.

DesktopTextControl.MouseUp

MouseUp(X As Integer, Y As Integer)

The mouse button was released. Use the x and y parameters to determine if the mouse button was released within the control's boundaries.

Note

This event will not occur unless you return True in the MouseDown event. The return value is ignored.

The parameters x and y are local coordinates, i.e. they represent the position of the mouse click relative to the upper-left corner or the control. Mouse clicks that are released to the left or above a control are negative.

DesktopTextControl.MouseWheel

MouseWheel(X As Integer, Y As Integer, DeltaX As Integer, DeltaY As Integer) As Boolean

The mouse wheel has been moved.

The parameters X and Y are the mouse coordinates relative to the control that has received the event. The parameters DeltaX and DeltaY hold the number of scroll lines the wheel has been moved horizontally and vertically, as defined by the operating system. DeltaX is positive when the user scrolls right and negative when scrolling to the left. DeltaY is positive when the user scrolls down and negative when scrolling up.

Returns a Boolean. Return True to prevent the event from propagating further.

DesktopTextControl.Opening

Opening

The control is about to be displayed. Use this event to initialize a control.

The Opening event is called after the Constructor.

Be warned that initializing control property values using the Constructor instead of the Opening event may result in those property values being overwritten by what is set in the Inspector. For best results, use the Opening event for control initialization rather than the control Constructor.

If the control is supposed to handle drag and drop, you need to tell it which type of item it needs to be able to handle. The following example informs the control that pictures and files can be dropped on it. The type of the file it needs to support is specified via the File Types Editor.

Sub Opening()
  Me.AcceptPictureDrop
  Me.AcceptFileDrop("JPEG")
End Sub

DesktopTextControl.SelectionChanged

SelectionChanged

The range of characters highlighted has changed.

DesktopTextControl.TextChanged

TextChanged

The Text property has been changed.

DesktopTextControl.ValidationFailed

ValidationFailed(InvalidText As String, StartPosition As Integer)

The user has tried to enter a character that is prohibited by the Mask property.

InvalidText is the entire character string up to and including the invalid text. StartPosition is the starting character position in which the actual invalid text was entered. The first character is numbered 1. If no code is provided in this event and a validation error occurs, you will hear the default system beep.

Notes

DesktopTextControl is the base class for both DesktopTextArea and DesktopTextField. DesktopTextControl is an abstract class and it is not intended for instantiation. Use DesktopTextArea for multiline and styled controls and DesktopTextField for single line text fields.

Execution order of menuhandlers

The intrinsic control menu handlers (such as DesktopTextField.SelectAll) are handled after any user-defined menu handlers on the TextField subclass (if it was subclassed). This means that if you have a SelectAll handler on the Window of the DesktopTextField, it will no longer be called when the DesktopTextField has focus, because the DesktopTextField will now handle it first. In this situation, create a DesktopTextField subclass that defines its own SelectAll handler, and handle the desired behavior there.

Masks

Use the ValidationMask property to filter user input on a character-by-character basis and add formatting characters. For example, a mask for a Telephone number field can add parentheses, spaces, and dashes as literals, that are used for formatting, and the digit mask symbol '#' to restrict entry to numbers only. See ValidationMask for details.

Compatibility

Desktop projects on all supported operating systems.