Class

DesktopChart

Description

Displays data you provide in chart form of various types.

Methods

Name

Parameters

Returns

Shared

AddDataset

dataset As ChartDataset

AddDatasetAt

index As Integer, Dataset As ChartDataset

AddDatasets

Datasets() As ChartDataset

AddLabel

name As String

AddLabelAt

index As String, name As String

AddLabels

names() As String

Close

DatasetAt

index As Integer

ChartDataset

DrawInto

g As Graphics, x As Integer, y As Integer

LabelAt

index As Integer

String

RemoveAllDatasets

RemoveAllLabels

RemoveDatasetAt

index As Integer

RemoveLabelAt

index As Integer

SetFocus

Enumerations

DesktopChart.Modes

Modes

The various types of charts available.

Enum

Bar

Bubble

Doughnut

Line

Pie

PolarArea

Radar

Scatter

Property descriptions

DesktopChart.AllowPopover

AllowPopover As Boolean

If True, a popover will be displayed when the user positions the mouse over items that have additional information.

The default value is True.

DesktopChart.BackgroundColor

BackgroundColor As ColorGroup

The color of the background of the chart.

DesktopChart.DatasetCount

DatasetCount As Integer

The number of datasets that have been added to the chart.

This property is read-only.

DesktopChart.Enabled

Enabled As Boolean

When True the control is drawn enabled and responds to user action. When False, the control appears as disabled and does not respond to user actions.

DesktopChart.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 FontName.

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"

DesktopChart.FontSize

FontSize As Double

Point size of the font used to display the caption.

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

DesktopChart.GridColor

GridColor As ColorGroup

The color of the chart's grid.

DesktopChart.HasLegend

HasLegend As Boolean

If True, the chart's legend will be displayed.

DesktopChart.Height

Height As Integer

The height (in points) of the control.

DesktopChart.Left

Left As Integer

The position of the left side of the control in pixels, relative to the window.

DesktopChart.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 is read-only.

DesktopChart.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.

This property is read-only.

DesktopChart.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 is read-only.

DesktopChart.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.

This property is read-only.

DesktopChart.Mode

Mode As Modes

Indicates the type of chart the control is currently displaying.

This property is read-only.

Labels are required for a Bar chart to draw.

This example checks the mode of the chart:

If Chart1.Mode = DesktopChart.Modes.Bar then
  Chart1.Title = "Sales Bar Chart"
End If

DesktopChart.Name

Name As String

The name of the control.

This property is read-only.

DesktopChart.Parent

Parent As Object

Used to get the control's parent control or page. If the parent control is a DesktopContainer, then it returns the DesktopContainer. If it is on a DesktopWindow, it returns the DesktopWindow.

This property is read-only.

DesktopChart.PopoverBackgroundColor

PopoverBackgroundColor As ColorGroup

The background color of the chart's popover.

DesktopChart.PopoverTextColor

PopoverTextColor As ColorGroup

The color of text in the chart's popover.

DesktopChart.TabIndex

TabIndex As Integer

The control's position in the Tab Order. The control with a TabIndex of 0 is the first control to get the focus when the window opens.

This example sets the control's TabIndex.

Me.TabIndex = 2

DesktopChart.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

DesktopChart.Title

Title As String

The title of the chart.

DesktopChart.Tooltip

Tooltip As String

Text of a message displayed as a tooltip.

The tip is displayed when the user places the mouse on the control and leaves it there.

This code in the Opening event of a Button sets the tooltip:

Me.Tooltip = "Save changes"

DesktopChart.Top

Top As Integer

The top of the control in local coordinates relative to the window.

DesktopChart.Visible

Visible As Boolean

If True, the control is drawn. If False, it's not.

Hide a control based on a checkbox setting:

If ShowEmailCheckbox.Value Then
  EmailField.Visible = True
Else
  EmailField.Visible = False
End If

DesktopChart.Width

Width As Integer

The width (in points) of the control.

This code in the Shown event handler increases the size of the control:

Me.Width = Me.Width + 50

Method descriptions

DesktopChart.AddDataset

AddDataset(dataset As ChartDataset)

Adds the dataset to the chart. Incompatible datasets are ignored.

DesktopChart.AddDatasetAt

AddDatasetAt(index As Integer, dataset As ChartDataset)

Adds the dataset to the chart at the index passed. Incompatible datasets are ignored.

DesktopChart.AddDatasets

AddDatasets(datasets() As ChartDataset)

Adds the array of datasets to the chart.

DesktopChart.AddLabel

AddLabel(name As String)

Adds the label to the chart.

DesktopChart.AddLabelAt

AddLabelAt(index As String, name As String)

Adds the label to the chart at the index passed.

DesktopChart.AddLabels

AddLabels(names() As String)

Adds the array of labels to the chart.

DesktopChart.Close

Close

Closes the control.

DesktopChart.DatasetAt

DatasetAt(index As Integer) As ChartDataset

Returns the ChartDataset at the index passed.

DesktopChart.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

DesktopChart.LabelAt

LabelAt(index As Integer) As String

Returns the label at the index passed.

DesktopChart.RemoveAllDatasets

RemoveAllDatasets

Removes all datasets from the chart.

DesktopChart.RemoveAllLabels

RemoveAllLabels

Removes all labels from the chart.

DesktopChart.RemoveDatasetAt

RemoveDatasetAt(index As Integer)

Removes the ChartDataset at the index passed.

DesktopChart.RemoveLabelAt

RemoveLabelAt(index As Integer)

Removes the label at the index passed.

DesktopChart.SetFocus

SetFocus

Sets the focus to the DesktopChart control.

Event descriptions

DesktopChart.Activated

Activated

The control is activated. In a single window interface, the Activate event fires when the parent window is activated. See the DesktopApplication and DesktopWindow Activate events.

This can be because the app is launched or a window belonging to another app is no longer frontmost (active). The Deactivate event fires when another window becomes active. In a single window interface, the Activate event fires when the window is activated, e.g., when the app first displays the window.

DesktopChart.Closing

Closing

The control is about to be removed from the window either because the window is closing or the control's Close method was called.

DesktopChart.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

DesktopChart.ContextualMenuSelected

ContextualMenuSelected(selectedItem As DesktopMenuItem)

Called when selectedItem is chosen from a contextual menu.

This code populates a contextual menu in the Opening event of a Chart control:

Var menu As New DesktopMenuItem

menu.AddMenuItem("One")
menu.AddMenuItem("Two")
menu.AddMenuItem("Three")
Me.ContextualMenu = menu

The menu selection is then handled by the ContextualMenuSelected event when the user right-clicks on the control. For example, it can be of the form:

Select case selectedItem.Text
Case "One"
  MessageBox("One")
Case "Two"
  MessageBox("Two")
Case "Three"
  MessageBox("Three")
End Select

DesktopChart.Deactivated

Deactivated

The DesktopChart is deactivated. See the DesktopApplication and DesktopWindow Deactivated events.

In a multiple window interface, the Deactivated event fires when the parent window is deactivated because another window has been brought to the front or a window belonging to another app becomes frontmost. In a single window app, the Deactivated event fires when a window belonging to another app becomes frontmost.

DesktopChart.DragEnter

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

Fires when the passed DragItem enters the DesktopChart control.

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

DesktopChart.DragExit

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

Fires when the passed DragItem exits the DesktopChart control.

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

DesktopChart.DragOver

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

Fires when the DragItem is over the DesktopChart control.

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.

DesktopChart.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

DesktopChart.Error

Error(DataSet As ChartDataSet)

The chart either has no room to display the data or is too small to draw the grid. The DataSet is the ChartDataSet assigned to the control.

DesktopChart.FocusLost

FocusLost

The control has lost the focus.

This property must be set to True for the control to be capable of getting then losing 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.

DesktopChart.FocusReceived

FocusReceived

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

This property must be set to True for the control to be capable of getting the focus.

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.

DesktopChart.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.

DesktopChart.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.

DesktopChart.MenuBarSelected

MenuBarSelected

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

DesktopChart.Opening

Opening

The control has been created and the page is opening but has not been sent to the browser yet.

The Opening event handler can be used to initialize non-visual properties and settings for controls.

DesktopChart.Pressed

Pressed(dataset As ChartDataset, index As Integer)

The user pressed on a part of the chart that represents data from the dataset.

Compatibility

Desktop projects on all supported operating systems.