Attributes Affecting Theme Appearance

2-60 Oracle Fusion Middleware Users Guide for Oracle MapViewer } } protected NSDataSet readFromUrlString url { log.errorurl not supported yet.; return null; } protected NSRow buildRowString line, String delimiter { ifline==null || line.length1 return null; String[] fields = line.splitdelimiter; iffields==null || fields.length==0 return null; Field[] row = new Field[fields.length]; Field a = new Fieldfields[0]; a.setKeytrue; row[0] = a; for int i = 1; i fields.length; i++ { try{ double d = Double.parseDoublefields[i]; a = new Fieldd; row[i] = a; }catchException e { log.warninvalid row field key=+fields[0]+; return null; } } return new NSRowrow; } }

2.3.11 Attributes Affecting Theme Appearance

Some attributes of the theme element affect only the appearance of the map display, rather than determining the data to be associated with the theme. These appearance-related attributes control whether and how the theme is processed and rendered when a map is generated. Examples include the following attributes: ■ min_scale and max_scale determine whether or not a theme is displayed at various map scales levels of resolution. For example, if you are displaying a map of streets, there are certain map scales at which the streets would become too dense for a usable display, such as when viewing an entire state or province. In this case, you should create a theme for streets, and specify minimum and maximum scale values to ensure that individual streets affected by the theme are displayed when the scale is appropriate and otherwise are not displayed. ■ labels_always_on determines whether or not labels for the theme will be displayed if they would overlap another label. By choosing appropriate labels_ MapViewer Concepts 2-61 always_on values and choosing an appropriate order of themes to be processed within a map request, you can control how cluttered the labels might become and which labels have priority in getting displayed. ■ fast_unpickle determines the unpickling unstreaming method to be used, which can involve a trade-off between performance and precision in the display. ■ fixed_svglabel, visible_in_svg, selectable_in_svg, onclick, onmousemove, onmouseover, and onmouseout affect the appearance of SVG maps. To specify any appearance-related attributes, use the theme element described in Section 3.2.20 with the XML API or the JavaBean-based API see especially Section 4.3 .

2.4 Maps

A map can consist of a combination of elements and attributes, such as the following: ■ Background image ■ Title ■ Legend ■ Query window ■ Footnote such as for a copyright notice ■ Base map ■ Predefined themes in addition to any in the base map ■ JDBC themes with dynamic queries ■ Dynamically defined temporary styles These elements and attributes, when specified in a map request, define the content and appearance of the generated map. Chapter 3 contains detailed information about the available elements and attributes for a map request. A map can have a base map and a stack of themes rendered on top of each other in a window. A map has an associated coordinate system that all themes in the map must share. For example, if the map coordinate system is 8307 for Longitude Latitude WGS 84, the most common system used for GPS devices, all themes in the map must have geometries defined using that coordinate system. You can add themes to a map by specifying a base map name or by using the programming interface to add themes. The order in which the themes are added determines the order in which they are rendered, with the last specified theme on top, so be sure you know which themes you want in the background and foreground. All base map names and definitions for a database user are stored in that user’s USER_ SDO_MAPS view, which is described in Section 2.9 and Section 2.9.1 . The DEFINITION column in the USER_SDO_MAPS view contains an XML definition of a base map. Example 2–43 shows a base map definition. Example 2–43 XML Definition of a Base Map ?xml version=1.0 ? map_definition theme name=theme_us_states min_scale=10 max_scale=0