Class

WebMapViewer

Description

A control for viewing maps loaded via a map provider like Google. It is initially centered at the position specified by Latitude, Longitude.

Methods

Name

Parameters

Returns

Shared

AddLocation

Location As WebMapLocation

Close

ExecuteJavaScript

Script As String

GoToLocation

Location As WebMapLocation

GotoURL

Url As String, inNewWindow As Boolean = False

RemoveLocation

Location As WebMapLocation

Search

Query As String

SetFocus

UpdateBrowser

Events

Name

Parameters

Returns

Closed

ContextualMenuSelected

hitItem As WebMenuItem

Hidden

Opening

Shown

Enumerations

WebMapViewer.MapTypes

MapTypes

Specifies the type of map to be displayed. For example, roadmap versus satellite.

Enum

Description

RoadMap

Shows roads and points of interest. This type is good for showing locations and directions.

Satellite

Shows satellite photos rather than roads and locations.

WebMapViewer.Modes

Modes

Specifies the mode in which the map will work. For example, showing a location versus showing directions.

Enum

Description

Place

Displays a map pin at a particular place or address, such as a landmark, business, geographic feature, or town.

Directions

Displays the path between two or more specified points on the map, as well as the distance and travel time.

Search

Displays results for a search across the visible map region. It's recommended that a location for the search be defined, either by including a location in the search term (record+stores+in+Seattle) or by including a center and zoom parameter to bound the search.

View

Returns a map with no markers or directions.

StreetView

Provides a viewer that renders the resulting panorama as a sphere with a camera at its center. You can manipulate the camera to control the zoom and the orientation of the camera.

Property descriptions

WebMapViewer.AllowFullScreen

AllowFullScreen As Boolean

When True provides a widget that allows the user to toggle between the map view consuming the designated space on the page versus consuming the entire browser window.

WebMapViewer.APIKey

APIKey As String

Specifies the APIKey to use with Google Maps.

Although the APIKey property existed before 2017r1, those older versions are not compatible with current versions of the Google Maps API. As an alternative for older versions you can try using the Google Maps JavaScript API in a WebHTMLViewer.

Google Maps runs in a sort of demo mode without an API Key. Visit the Google Maps API Key page to get your own API Key.

Always set your API key, usually in the Open event:

Me.APIKey = "<YourGoogleMapsAPIKey>"

WebMapViewer.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.Value
Case "One"
  MessageBox("One")
Case "Two"
  MessageBox("Two")
Case "Three"
  MessageBox("Three")
End Select

WebMapViewer.ControlID

ControlID As String

Identifies the control on a per session basis.

This property is read-only.

WebMapViewer.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

WebMapViewer.Height

Height As Integer

The height (in pixels) of the control.

WebMapViewer.Indicator

Indicator As Indicators

The color scheme for the control.

When a WebButton's Default or Cancel properties are True, the Indictor property is ignored as Default and Cancel buttons have a default indicator.

WebMapViewer.Latitude

Latitude As Double

Sets or Gets the latitude of the center of the map being displayed. Because you would normally want to set both the latitude and longitude, you must also call the UpdateBrowser method to send the changes to the browser.

Set the map to a specific latitude and longitude:

MapViewer1.Latitude = 38.8977
MapViewer1.Longitude = -77.0366
MapViewer1.Update

WebMapViewer.Left

Left As Integer

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

WebMapViewer.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.

This property is read-only.

WebMapViewer.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).

This property is read-only.

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.

WebMapViewer.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.

This property is read-only.

WebMapViewer.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.

This property is read-only.

WebMapViewer.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.

This property is read-only.

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.

WebMapViewer.Longitude

Longitude As Double

Sets or Gets the longitude of the center of the map being displayed. Because you would normally want to set both the latitude and longitude, you must also call the UpdateBrowser method to send the changes to the browser.

Set the map to a specific latitude and longitude:

MapViewer1.Latitude = 38.8977
MapViewer1.Longitude = -77.0366
MapViewer1.Update

WebMapViewer.MapType

MapType As MapTypes

Sets or gets the type of map being displayed.

Change the map type to a road map:

Me.MapType = WebMapViewer.MapTypes.RoadMap

WebMapViewer.Mode

Mode As Modes

Sets or gets the mode of the map being displayed.

Change the map type to street view:

Me.Mode = WebMapViewer.Modes.StreetView

WebMapViewer.ModeData

ModeData As String

The data required for the Mode when it's set to Place or Search.

WebMapViewer.Name

Name As String

The name of the control.

This property is read-only.

WebMapViewer.Page

Page As WebPage

Identifies the web page that contains the control.

This property is read-only.

WebMapViewer.Parent

Parent As WebControl

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.

WebMapViewer.Style

Style As WebStyle

The WebStyle for the control.

In the Pressed event of a WebButton, set the text to bold:

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

WebMapViewer.TabIndex

TabIndex As Integer

The WebUIControl'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

WebMapViewer.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 Shown event of a Button sets the tooltip:

Me.Tooltip = "Save changes"

WebMapViewer.Top

Top As Integer

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

WebMapViewer.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

WebMapViewer.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

WebMapViewer.Zoom

Zoom As Integer

Sets or gets the zoom level of the map being displayed.

Typically the Zoom is a value from 1 (minimum zoom) to 20 (maximum zoom).

Zoom in the current map location to the maximum zoom, which is typically street-level:

Me.Zoom = 20

Method descriptions

WebMapViewer.AddLocation

AddLocation(Location As WebMapLocation)

Adds a WebMapLocation object to the map, indicated by a pin.

Add a location to the map:

Var location As New WebMapLocation("Fenway Park, Boston, MA")
WebMapViewer1.AddLocation(location)

WebMapViewer.Close

Close

Removes the control from the page.

WebMapViewer.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();")

WebMapViewer.GoToLocation

GoToLocation(Location As WebMapLocation)

Centers the map on the passed WebMapLocation.

Centers the map on the specific location:

Var location As New WebMapLocation("Fenway Park, Boston, MA")
MapViewer1.GoToLocation(location)

WebMapViewer.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)

WebMapViewer.RemoveLocation

RemoveLocation(Location As WebMapLocation)

Removes a WebMapLocation object from the map. If the location is visible on the map, the icon is also removed.

If Location is a property of the web page for a location that has been previously added, you can remove it:

If Location Is Not Nil Then
  MapViewer1.RemoveLocation(location)
End If

WebMapViewer.Search

Search(Query As String)

Performs a maps query based upon the query passed.

WebMapViewer.SetFocus

SetFocus

Sets the focus to the Control.

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

If UserNameField.Value = "" Then
  MessageBox("Please enter your UserName.")
  UserNameField.SetFocus
  Return
End If

WebMapViewer.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 ProgressBar and then forces the updated ProgressBar to be sent to the browser via UpdateBrowser.

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

Event descriptions

WebMapViewer.Closed

Closed

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

WebMapViewer.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.Value
Case "One"
  MessageBox("One")
Case "Two"
  MessageBox("Two")
Case "Three"
  MessageBox("Three")
End Select

WebMapViewer.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.

WebMapViewer.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.

WebMapViewer.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.Value = "Welcome!"
Else
  Me.Value = "Welcome, " + Session.UserName
End If

Notes

Warning

As of June 2018, Google Maps requires an API Key. You will need to set the APIKey property to your API Key in order for WebMapViewer to display any maps.

The WebMapViewer control is based on Google maps. As such, has the same strengths and limitations of Google Maps.

If errors occur during initialization of the WebMapViewer and you are running in debug mode, the error messages will appear in the IDE Messages pane.

Google maps api key

As of June 2018, Google Maps requires an API Key. Visit the Google Maps docs for more information on usage:

Google Maps Platform User Guide

The mapviewer user interface

When you add a WebMapViewer control to a WebPage, it comes with widgets to manipulate the zoom, the type, and the location. The zoom level is adjusted via the Slider control on the left and you can change the location by dragging with the hand (top-left). The type of map is changed by clicking the segmented control on the top-right corner. When you change the type (for example, from Map to Satellite), a check box appears below the Segmented Control to toggle that view type. If Map is selected, a Terrain checkbox appears to show or hide terrain features; if Satellite is selected, a checkbox appears to show or hide labels.

Sample code

Create and display a location on the map:

Var location As New WebMapLocation("Fenway Park, Boston, MA")
MapViewer1.GoToLocation(location)

Display a location entered by the user (in the LocationField TextField) on the map:

MapViewer1.Search(LocationField.Value)

Compatibility

Web projects on all supported operating systems.

See also

WebUIControl parent class; WebMapLocation class.