7 Getting Started with Developing Java Applications

You can hold down the Shift key and then hover over a variable or method to show its definition in a ghost window. This feature makes it convenient to quickly view code without moving cursor focus from your current code.

Figure 7-1 Code Peek

While dragging the vertical scroll bar, a small tip window appears next to the bar, revealing the methods that are visible or partially visible on screen. This enables you to more easily see what methods are in view while quickly scrolling. You can also see the name of the method whose beginning is not immediately in view.

An InfoTip is a pop-up window that reveals additional detail about an item in the application, for example, text in the Java Source Code editor and the overview gutter. You display the InfoTip by pointing or hovering over the item with your mouse cursor. It remains visible until you move the mouse away or click elsewhere in the UI.

Figure 7-2 InfoTips

To search incrementally, from the main menu choose Search > Incremental Find Forward or Search > Incremental Find Backward. Begin typing in the dialog that displays. As you type, the cursor jumps to the next instance of that particular letter combination, either forward or backward. The search does not support wildcards.

Shortcut keys, or accelerators, are combinations of keys that you can use to navigate or to perform certain operations using the keyboard instead of the mouse. You can select from a variety of predefined keymaps or define your own accelerators.

To view or change existing accelerators, to define new accelerators, or to load preset keymaps, from the main menu choose Tools, then Preferences to open the Preferences dialog and then navigate to the Shortcut Keys page. To view or change accelerators for the editor, select Code Editor from the Category list.

Note that block commenting is indicated by Toggle Line Comments. It is defined in the default keymap as Ctrl-Shift-Slash or Ctrl-Slash.

For more information, see Keyboard Navigation in .

While bookmarking code:

• You can see a list of all bookmarks you have created in a Bookmarks window. This window appears when you click the Go to Bookmark icon. This window also displays the line number and method name that contains the bookmark.

  Figure 7-3 Go to Bookmark Icon

  

• You can create numbered bookmarks using the keyboard shortcut Ctrl+Shift+<number>. You can quickly navigate to that bookmark by pressing Ctrl+<number>.

For more information, see How to Set Bookmarks in Source Files.

To navigate to the source for any identifier in an open Java file, right-click on the identifier you would like to browse and choose Go to Declaration. Alternatively, you can hold down the Ctrl key and click on an identifier to navigate to its source. If the source is not available, JDeveloper will reverse-engineer the class file. You may browse imported classes and interfaces, member fields and methods, and local variables. If you are browsing a method or constructor invocation, this declaration search will resolve the types in order to determine the correct method or constructor invocation. For instance, the following code revokes the declaration search at SetText. It brings up the source code for javax.swing.JButton, with the SetText() method displayed.

import javax.swing.JButton
...
JButton b1 = new JButton();
...
b1.SetText: ('OK');

If the identifier cannot be browsed or if there is nothing at that cursor position, this search command on the context-sensitive menu will be disabled. If JDeveloper is unable to locate the appropriate location to jump to or if the identifier cannot be browsed due to access restrictions (for example, private members), the Java Source Editor's status bar will display a message indicating so.

Code templates are sections of pre-written code that can be conveniently inserted into source file to avoid typing it in manually. Templates can intelligently modify the inserted code to suit its surrounding code, and imports required by code templates are automatically imported.

A complete list of all code templates is available in the Code Editor Help. To edit or create code templates, or to view or change accelerators, from the main menu choose Tools > Preferences to open the Preferences dialog and then navigate to the appropriate page.

For more information, see How to Use Code Templates.

You can customize the behavior of the Java Source Editor using the Preferences Dialog. You can also use the Preferences Dialog to specify settings for the general source editing environment. For more information, see How to Set Preferences for the Source Editor.

To set the options for Code Insight as it applies to Java:

The Java Source Editor displays Java source files, and facilitates editing of Java code. Icons that perform various features are located at the top of the Java Source Editor, as described in Table 7-1.

Clicking the Quick Outline Toolbar icon (Figure 7-4) to the right of the Find field in the Java source editor displays the Quick Outline window shown in Figure 7-5.

Figure 7-4 Quick Outline Icon

This window floats just above the code and contains a tree of the available methods and fields of the current class and its super classes. You can instantly start typing in a filter field to reduce the visible items, allowing quick and easy selection for navigation to the place.

Figure 7-5 Quick Outline Window

Table 7-2 lists the available icons and options.