Class

WebProgressBar

Description

This control shows determinate and indeterminate progress. It's the web equivalent of the desktop ProgressBar control and is basically identical in functionality and API.

Methods

Name

Parameters

Returns

Shared

Close

CSSClasses

WebCSSClasses

ExecuteJavaScript

Script As String

GotoURL

Url As String, inNewWindow As Boolean = False

SetFocus

Style

WebStyle

Assigns style As WebStyle

UpdateBrowser

Events

Name

Parameters

Returns

Closed

ContextualMenuSelected

hitItem As WebMenuItem

Hidden

Opening

Shown

Property descriptions

WebProgressBar.AllowAnimation

AllowAnimation As Boolean

If True, the ProgressBar will animate when updating. If False, it will not.

Setting this to False can be useful when running on mobile devices as animation can be CPU-intensive and thus battery draining.

WebProgressBar.ContextualMenu

ContextualMenu As WebMenuItem

If you assign a WebMenuItem to the control, it will be displayed when the user right-clicks the control.

On a WebPage, you can disable/remove the default contextual menu by an empty WebMenuItem class object to this property.

This code populates a contextual menu in the Shown event of the control.

Var menu As New WebMenuItem

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

WebProgressBar.ControlID

ControlID As String

Identifies the control on a per session basis.

This property is read-only.

WebProgressBar.Enabled

Enabled As Boolean

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

In the case of WebTimer, when set to False this disables and stops the WebTimer. When set to True, it starts the WebTimer.

Disable a button when a check box value changes:

If AllowSaveCheckBox.Value Then
  SaveButton.Enabled = True
Else
  AllowSaveButton.Enabled = False
End If

WebProgressBar.Height

Height As Integer

The height (in pixels) of the control.

WebProgressBar.Indeterminate

Indeterminate As Boolean

If True, the control shows indeterminate progress rather than determinate progress.

The appearance of an indeterminate progress bar varies depending on the platform and browser being used. These types of progress bars are used to indicate a long-running task with an unknown duration.

This line sets indeterminate progress.

Me.Indeterminate = True

WebProgressBar.Indicator

Indicator As Indicators

The color scheme for the control.

WebProgressBar.Left

Left As Integer

The position of the left side of the WebUIControl in pixels, relative to the web page.

WebProgressBar.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 web page.

WebProgressBar.LockHorizontal

LockHorizontal As Boolean

LockHorizontal overrides LockLeft and LockRight. It allows you to proportionally lock a control's position to the center of its parent control (or web page).

For example, if you place a control in the center of the page and sets both LockHorizontal and LockVertical, the control will stay in the center of the page.

WebProgressBar.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 web page.

WebProgressBar.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 web page.

WebProgressBar.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 web page.

WebProgressBar.LockVertical

LockVertical As Boolean

LockVertical overrides LockTop and LockBottom. It allows you to proportionally lock a control's position to keep it centered within the parent control or web page.

For example, if you place a control in the center of the page, and sets both LockHorizontal and LockVertical, the control will stay in the center of the page.

WebProgressBar.MaximumValue

MaximumValue As Integer

The maximum value of the progress bar.

When the Value property reaches this maximum value, the progress bar displays as completely filled in.

This line of code sets the maximum value of the progress bar to 350:

ProgressBar1.MaximuValue = 350

WebProgressBar.Name

Name As String

The name of the control.

This property is read-only.

WebProgressBar.PanelIndex

PanelIndex As Integer

If the control has been placed on a WebTabPanel or WebPagePanel 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 WebTabPanel or WebPagePanel control, it returns the panel number. If the control is not on a WebPagePanel or WebTabPanel, 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 SelectedPanelIndex.

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

MessageBox(Me.SelectedPanelIndex.ToString)

WebProgressBar.Page

Page As WebPage

Identifies the web page that contains the control.

This property is read-only.

WebProgressBar.Parent

Parent As WebView

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

This property is read-only.

WebProgressBar.TabIndex

TabIndex As Integer

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

This example sets the control's TabIndex.

Me.TabIndex = 2

WebProgressBar.Tooltip

Tooltip As WebToolTip

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 Shown event of a Button sets the tooltip:

Me.Tooltip = "Save changes"

WebProgressBar.Top

Top As Integer

The top of the control in local coordinates relative to the web page.

WebProgressBar.Value

Value As Integer

The current value of the progress bar.

This example is in the Opening event of a Progress Bar. It sets the maximum value and initializes the current value to 0.

Me.Value = 0
Me.MaximumValue = 100

On a WebTimer with a period of 1000, add this code to its Action event handler to increase the Progress Bar value about once a second:

mProgressValue = mProgressValue + 1 ' a property of the web page
If mProgressValue <= ProgressBar1.MaximumValue Then
  ProgressBar1.Value = mProgressValue
Else
  Me.Enabled = False
End If

WebProgressBar.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

WebProgressBar.Width

Width As Integer

The width (in pixels) of the web control.

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

Me.Width = Me.Width + 50

Method descriptions

WebProgressBar.Close

Close

Removes the control from the page.

WebProgressBar.CSSClasses

CSSClasses

Returns the instance of WebCSSClasses for this control allowing you to add CSS classes to and remove CSS classes from the control.

WebProgressBar.ExecuteJavaScript

ExecuteJavaScript(Script As String)

Executes the JavaScript passed. The JavaScript passed can call a JavaScript function in a WebPageSource control.

The Xojo web framework uses EcmaScript 6 which is more strict than previous versions of JavaScript. For more details, see the EcmaScript 6 documentation.

This code in the Pressed event of a Button displays an alert using JavaScript:

Me.ExecuteJavaScript("alert('Hello!');")

This code will select the text in a WebTextField (or WebTextArea):

WebTextField1.ExecuteJavascript("document.getElementById('" + _
  WebTextField1.ControlID + "_inner').select();")

WebProgressBar.GotoURL

GotoURL(Url As String, inNewWindow As Boolean = False)

Opens the passed URL in place of the current web page or downloads a file. If InNewWindow is True, the browser is asked to open the URL in a new window.

If the browser has popup windows disabled and InNewWindow is True, the method silently fails and the page is not shown.

If InNewWindow is False, the running web app is replaced with the specified URL. If you want to display an external web site within your web app, use the WebHTMLViewer control.

Display a web site in a new popup window:

Me.GotoURL("http://www.wikipedia.org", True)

WebProgressBar.SetFocus

SetFocus

Sets the focus to the Control.

This code checks for a required value when a button is pressed:

If UserNameField.Text.IsEmpty Then
  MessageBox("Please enter your UserName.")
  UserNameField.SetFocus
  Return
End If

WebProgressBar.Style

Style As WebStyle

Returns the WebStyle for the control.

Style(Assigns style As WebStyle)

Assigns the style to the control.

In this example, in any event of the control, set the text to bold:

Var style As New WebStyle
style.Bold = True
Me.Style = style

WebProgressBar.UpdateBrowser

UpdateBrowser

Forces the current values of the control to be sent to the browser.

This method is useful when you are computing values in a loop and wish to update the browser immediately rather than wait until the current method ends.

This code iterates through a RowSet of database rows, updates a WebProgressBar and then forces the updated WebProgressBar to be sent to the browser via UpdateBrowser.

ProgressBar1.MaximumValue = SalesData.RowCount
For Each row As DatabaseRow in SalesData
 AnalyzeSales(row)
 ProgressBar1.Value = ProgressBar1.Value + 1
 ProgressBar1.UpdateBrowser
Next

Event descriptions

WebProgressBar.Closed

Closed

The control has been removed from the browser either because the page has closed or the control's Close method was called.

WebProgressBar.ContextualMenuSelected

ContextualMenuSelected(hitItem As WebMenuItem)

Called when a contextual menu item is selected. This selected item is contained in hitItem.

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

Var menu As New WebMenuItem

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

WebProgressBar.Hidden

Hidden

The control is about to become no longer visible. This could be because the page is being closed, is being replaced as the foreground page by another page or because the control or a parent control's Visible property has been set to False.

Note

This event is equivalent to the DesktopWindow.Deactivated event in a desktop app.

WebProgressBar.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.

In most cases, you should use the Shown event to initialize controls.

WebProgressBar.Shown

Shown

The control has appeared on the currently displayed page. This could be because its parent page just finished loading, its parent page has come to the foreground or the control is now visible having been previously invisible because it or its parent control's Visible property has been set to True.

Use the Shown event for initializing your controls or doing anything that would interact with other controls or user interface elements on the web page instead of the Opening event.

Note

This event is the web equivalent to the DesktopWindow.Activated event.

This code in the Shown event of a WebListBox adds 2 rows with 3 columns:

Me.RemoveAllRows
Me.AddRow("Row 1", "Bob", "Roberts")
Me.AddRow("Row 2", "Barb", "Reynolds")

This example sets the text of a label:

If Session.LoggedIn Then
  Me.Text = "Welcome!"
Else
  Me.Text = "Welcome, " + Session.UserName
End If

Notes

In order to move a ProgressBar, you will want to use a WebTimer or call UpdateBrowser inside your loop.

Sample code

On a WebTimer with a period of 1000, add this code to its Action event handler to increase the Value property about once a second:

progress = progress + 1 ' a property of the web page
If progress <= ProgressBar1.MaximumValue Then
  ProgressBar1.Value = progress
Else
  Me.Enabled = False
End If

Compatibility

Web projects on all supported operating systems.