Showing the map

Showing and hiding

The map is not loaded until you ask for it (MapVisible is False at start). These calls show it:

Call	What it does
GotoAddress(Address)	Shows the map at an address (looked up with the Google geocoding service) and puts a marker on it. An empty address hides the map
GotoLocation(LatLng, AAddMarker)	Shows the map at a position; the marker is added unless AAddMarker is False. A position of 0, 0 hides the map
ShowMap(Address) / ShowMap(LatLng)	Shows the map, at an address or at a position
HideMap	Clears the map (the page goes back to about:blank)

GotoAddress and GotoLocation can be called again and again: when the map is already visible they move it, without loading the page once more. The methods that draw on the map (markers, shapes) show it first if it is hidden, and wait until it is ready.

A position is a TLatLng record, with Latitude, Longitude and an optional Description that becomes the text of the marker. The two class functions TextToCoord and CoordToText convert a coordinate from and to text, always with the dot as decimal separator, whatever the regional settings of the machine.

Location.Latitude := TEdgeGoogleMapViewer.TextToCoord(Latitude.Text);
Longitude.Text := TEdgeGoogleMapViewer.CoordToText(Location.Longitude);

View mode and zoom

EdgeGoogleMapViewer.MapTypeId := mtHYBRID;
EdgeGoogleMapViewer.MapZoom := 12;

MapTypeId
mtROADMAP	The default road map
mtSATELLITE	Satellite images
mtHYBRID	Satellite images with the roads and the names
mtTERRAIN	A physical map of the terrain

MapZoom is the zoom level (15 by default). When the user zooms the map, the OnMapZoom event tells you the new value.

Layers

Property	Method
MapShowTrafficLayer	ShowTraffic(Boolean)
MapShowBicyclingLayer	ShowBicycling(Boolean)

The property sets the value to use when the map is shown; the method changes it on the map that is on screen. Setting the property while the map is visible does both.

Controls

Every control of the map can be shown or hidden:

Property	Default	Method
MapShowZoomControl	True	ShowZoomControl
MapShowTypeControl	True	ShowMapTypeControl
MapShowFullScreenControl	True	ShowFullScreenControl
MapShowStreetViewControl	False	ShowStreetViewControl
MapShowPanControl	True
MapShowScaleControl	True
MapShowoverviewMapControl	True

When the map goes full screen the form around it usually has to give up its space: the OnContainsFullScreenElementChanged event of the browser tells you so, and the demo hides its panels in it.

Colour scheme

EdgeGoogleMapViewer.MapColorScheme := csDARK;   // or csLIGHT

The light and dark themes of the map. Changing it while the map is visible creates the map again, so a marker put before is no longer there.

Printing

ShowPrintUI opens the print panel of the browser, embedded in the form: the user can print the map as it is on screen.