Forms

Window is an empty frame to hold your object and it is the outermost boundary for a form. Block is a logical container that holds form objects such as data items and control buttons. There are two types of block: Data Block and Control Block. A Data Block is a link to your database information and holds database data. A Control Block holds information that has nothing to do with database. A item could be a database column or none database item. A canvas is a place to hold the objects. The four types of canvases are: Content, Stacked, Tab, and Toolbar. All can coexist within a single window. A content canvas is the basic background for all windows. A stacked canvas lays on top of the others. A tab canvas is the same as stacked canvases with handy �tabs� at the top. It can simply move from one canvas to another. A toolbar canvas contains push buttons giving users quick access such as horizontal canvas or vertical canvas.

Oracle tools are somehow follow object oriented methodology. Although they are not pure object oriented but there are not far from it either. Each item in the Oracle tools can be identified as an object. To manipulate an object, you use Property Palette. As you can see from now on, you can do much without property palette. A Property Palette contains object properties. The contents of the Property Palette are referred to as the �Property sheet� for the object. You use the Property Palette to modify object properties. To open the Property Palette of an object, go to the object and right click on the mouse button then select Property Palette. The Property Palette provides complete control over your objects. It contains the property list of an object. Remember that the properties of an object can be changed to control the behavior of the object. The Item properties such as Tooltip, Hint, and Display Hint automatically, will be used to provide item-level assistance for the client and can be changed only from property palette. A text item appearance can be modified by manipulating properties such as Justification, or Format Mask properties. For controlling the data within a text item or display item, you can use properties such as Calculation Mode, and Lowest and Highest value

All your client functional requirements have been met. Now, your user focuses on the appearance of the application. They would like you to move and add some objects. They want their logo be displayed on each of their application tab canvas.

See Figure 17.

Your tasks are:

Perform some cosmetic layout changes.

Add a logo to their application.

Copy the logo to each tab canvas.

Run and test all user functional requirements.

FYou will learn how to: move objects around, create, copy, and paste logo, use tab canvas, use �object navigator,� use �Data Blocks,� use �Layout Editor,� use �Property Palette,� use �Run Form,� and �Execute Query.�

Figure 17

In the �Object Navigator� window, highlight Forms. Go to the Main menu and choose �File,� select �Open� to open an existing form (customer_orders_V14) in the folder.

Click on the �CUSTOMER_ORDERS_V14� form. The color changes to blue. Then change the name and then save the Form name as version 15 (customer_orders_v15). This way the original form is untouched.

To change an appearance of your application, it is a good idea to view it in the full screen. This way, you will have free space to move around.

To change a size of an object, either you can select the object and drag its handlers or you can open its property palette and change its width and/or height.

To move an object, you should select the object and when you see the handlers, position your cursor inside of the handlers and drag it to anywhere you wish to be. You can also press on the up, down, right and left arrow keys to move the selected object.

To select multiple objects, hold on the control key (Ctrl) and select one object at a time. You will see for each object you select there are 8 handlers. Or, you can move your cursor outside of objects, click and drag it until all the objects be inside of the box. Then release the mouse. All the objects in the box will be selected and will contain handlers.

To select multiple items that are next to each other, select the first one and then hold the shift key and select the last one, all the objects in between will be selected including the first and last.

To deselect an object or objects, just click anywhere on the canvas that it is outside of the selected area.

In the Layout Editor, you can use the Graphic Boiler Plate objects on the toolbar. They are on the shape of square, circle, etc. You can select them, then drop and resize them in your canvas.

Notice that in the Layout Editor on the vertical toolbar, there are two boxes that have �T� in them. One is bigger that the other. The smaller T (text) is for entry text. The big one T is for changing the text, background, and boarder colors. There are Fill Color, Line Color, and Text Color. If you select an object and then choose a color by clicking on the Fill Color icon, the object color will change. If you select a text and then choose a color by clicking on the Text Color icon, the text color will change. And it is the same for the Line Color icon. Try them. It is fun!

With all above functionalities and your creativities, you have lots of options to make the appearances of your application easy to understand.

See figure 17 and create the same picture on all your canvas tabs. You can create once and then copy and paste them.

Once you finish. Compile and run the application Form.

Click on �Execute query.�

Navigate through the application Form.

After testing the application, close the window and save the changes.

Questions:

Q: How do you use a window in the Form Module?

Q: Describe a Data Block in the Form Module.

Q: Describe a Control Block in the Form Module.

Q: What are the differences between a control block and a data block?

Q: How do you move an object or objects around in the Layout Editor?

Q: How do you copy and paste an object or objects in the Layout Editor and in the Object Navigator?

Q: How do you select a object or objects in the Layout Editor and in the Object Navigator?

Q: All your client functional requirements have been met. Now, your user focuses on the appearance of the application. They would like you to move and add some objects. They want their logo be displayed on each of their application tab canvas.

See Figure 17.

Your tasks are:

� Perform some cosmetic layout changes.

� Add a logo to their application.

� Copy the logo to each tab canvas.

� Run and test all user functional requirements.