Theme-level mouse event control functions can be defined for mouse-click, mouse-move, mouse-over, and mouse-out events.

A mouse-click event control function is called when theme feature selection is enabled and a feature of the theme is clicked. Each theme in the map can have its own mouse-click event control function. A theme-level mouse-click event control function is specified by the onclick attribute in the <theme> element in the map request or base map definition.

A mouse-move event control function is called whenever the mouse moves inside any feature of the theme. Each theme in the map can have its own mouse-move event control function. A theme-level mouse-move event control function is specified by the onmousemove attribute in the <theme> element in the map request or base map definition.

A mouse-over event control function is called whenever the mouse moves from outside a feature of the theme to inside a feature of the theme. Each theme in the map can have its own mouse-over event control function. A theme-level mouse-over event control function is specified by the onmouseover attribute in the <theme> element in the map request or base map definition.

A mouse-out event control function is called whenever the mouse moves out of a feature of the theme. Each theme in the map can have its own mouse-out event control function. A theme-level mouse-out event control function is specified by the onmouseout attribute in the <theme> element in the map request or base map definition.

These JavaScript functions must be defined in the web page that has the SVG map embedded. They take the following parameters:

• Theme name
• Key of the feature
• X-axis value of the point in the SVG viewer window where the mouse click occurred
• Y-axis value of the point in the SVG viewer window where the mouse click occurred

The key of the feature is the value of the key column from the base table, which is specified by the key_column attribute of the <theme> element in the map request or base map definition. ROWID is used as the default key column. For example, if the onclick attribute is set to selectCounty for the COUNTY theme, the following JavaScript function call is executed if the feature with rowid AAAHQDAABAAALk6Abm of the COUNTY theme is clicked on the SVG map at (100,120): selectCounty('COUNTY', 'AAAHQDAABAAALk6Abm', 100, 120).

The x-axis and y-axis values specify the coordinates inside the SVG viewer window where the mouse event occurred. The coordinate is defined in the local SVG viewer window coordinate system, which starts from (0,0) at the upper-left corner and ends at (width, height) at the lower-right corner.