ch33.htm

linux-unix130.linux.and.unix.ebooks130 linux and unix ebookslinuxLearning Linux - Collection of 12 E

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<A NAME="Heading21<FONT COLOR="#000077"><B>TIP:</B> </FONT>The middle mouse

	button invokes the Move button while the mouse is in the workspace. 

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<P>The Resize tool can change the size of any selected objects. When user interface

components from the bottom panel are initially created in the workspace, or when

selected components are composed with composition interface objects in the Composition

pull-down menu, they are displayed with their natural sizes. Resize simulates the

resizing of the application window during running of the application by letting users

drag and sweep the selected user interface component.</P>

<P>The Examine tool is used to look at attributes associated with the selected user

interface components. User interface components in <TT>ibuild</TT> contain attributes

that assist users in designing the layout of the interface, or in customizing the

generated code. Typically, the pop-up menu of the Examine tool shows Info and Props

entries as options.</P>

<P>Selecting Info causes a component-specific dialog box to pop up. Some of the common

attributes shown in the dialog box include the following: Base Class Name, which

describes the actual class name in the Interviews library to which the selected component

corresponds; and Class Name, which describes the user-specified class name of the

component.</P>

<P>If the value of Class Name is the same as that of the Base Class Name, the library

class is used for instantiating the component during code generation, or a set of

subclass files are generated to assist the customization of the new class, as described

earlier. Member Name describes the member name of the selected component as a member

variable of the closest enclosing MonoScene object. If the member name is exported,

the MonoScene object can access and manipulate this specific member instance. Canvas

Dimensions shows how much workspace (corresponding to actual screen space) in pixels

is actually allocated to the selected component. Natural Size, Shrinkability, and

Stretchability describe how much workspace the selected component wants to have.</P>

<P>The dialog box associated with the Props entry shows the selected component's

instance name and user-defined properties. Property specification takes the form

attribute:value.</P>

<P>In order to assist users in locating certain elements with certain member names

or instance names, <TT>ibuild</TT> enables a user to probe these attributes by Shift-left-clicking

on these elements when they are composed.</P>

<P>The Info entry has a pull-right menu that has class name, member name pairs in

it; the pull-right menu associated with the Props entry has class name, instance

name pairs.</P>

<P>Examining a GraphicBlock component causes a third Graphics entry to display in

the pop-up menu. Selecting this option causes graphics in the GraphicBlock to be

transferred to <TT>idraw</TT> for further refinement.</P>

<P>Graphics can be transferred back to <TT>ibuild</TT> by simply saving and quitting

<TT>idraw</TT>. Attributes associated with graphics in <TT>ibuild</TT> that are not

known to <TT>idraw</TT>, such as member name, are not lost in this process. This

option is supported only for backward compatibility. A much better technique is to

use the Narrow tool to narrow into GraphicBlocks, which changes <TT>ibuild</TT> into

<TT>idraw</TT> in the same window.



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<A NAME="Heading22<FONT COLOR="#000077"><B>NOTE:</B> </FONT>All machine-generated

	names are guaranteed to be unique in one session of <TT>ibuild</TT>. This property

	is lost with user-defined names, and when files generated by different sessions of

	<TT>ibuild</TT> are compiled together. 

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<P>The Relate tool provides a direct manipulation interface to semantically connect

compatible components. Typically, the end result of the Relate operation is the sharing

of attributes between the related components. For example, relating a scroller to

a file browser lets the scroller take the file browser's member name as its scrolling

target. Relating two push buttons causes the push buttons to mutually exclude each

other when receiving mouse clicks. In this case, the second (destination) push button

shares the ButtonState defined by the first (source) push button. Relate is also

very useful for semantically connecting Unidraw objects. For instance, an Editor

needs to be related to all enclosed Unidraw objects such as CommandControls, PanelControls,

and Viewers. In this case, the simplest way to establish the relations is to relate

the Editor with the object directly below it in the instance hierarchy, which causes

the relations to establish recursively.</P>

<P>The Edit tool manipulates text-based components. Engaging the Edit tool enables

users to perform editing on MenuItem, PushButton, RadioButton, CheckBox, Message,

stringEditor, PulldownMenu, PullrightMenu, CommandControl, HPanelControl, and VPanelControl

components.</P>

<P>The Magnify tool magnifies a portion of the interface specified by sweeping out

a rectangular area. The <TT>ibuild</TT> application magnifies the area to occupy

the entire screen, if possible.</P>

<P>The Narrow tool enables a user to navigate the structure of composed interfaces

in the same editor. Initially, <TT>ibuild</TT> starts at global scope. Engaging the

Narrow tool and selecting a component causes the hierarchy of the interface to be

displayed in a pop-up menu, with the highlighted entry showing the current scope.

Selecting a different entry causes the editor to switch to the scope of the selected

component. For instance, if a user chooses to narrow into an HBox, cutting or pasting

components in the workspace now affects only the HBox.



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<A NAME="Heading23<FONT COLOR="#000077"><B>NOTE:</B> </FONT>Leaf-level components

	don't define new scopes. Narrowing into graphics-related components such as GraphicBlocks,

	CommandControls, PanelControls, and Viewers transforms <TT>ibuild</TT> into <TT>idraw</TT>

	in the same window, in addition to switching the scope level. This feature is extremely

	useful because specifying structured graphics objects, class names, and member names

	can all be done within <TT>ibuild</TT>. Firing up <TT>idraw</TT> using the Examine

	tool is still supported for backward compatibility purposes. 

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<P>The Create Tool creates a prototypical tool of the current interface, and installs

it in the bottom tools palette. Users can choose between having the filename, a default

icon of the existing interface, or a customized bitmap as the new tool's icon. The

newly created tool can then be treated as a library tool for instantiation. This

allows domain-specific abstractions to be built and used across sessions of <TT>ibuild</TT>.</P>

<P>The Tools command enables a user to install tools to, or remove tools from, the

bottom tools panel. Users can choose to install (or remove) multiple tools from the

left (right) stringbrowser by selecting multiple entries and clicking the &lt;&lt;

Install (or Remove &gt;&gt;) button.</P>

<P>The Execute tool lets the user choose an executable from a file-chooser, and executes

the selected file without leaving <TT>ibuild</TT>.</P>

<P>The Quit command exits the current session of <TT>ibuild</TT>.



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<A NAME="Heading24<FONT COLOR="#000077"><B>NOTE:</B> </FONT>The Edit menu for

	<TT>ibuild</TT> contains commands that are very similar to those in <TT>idraw</TT>.

	Refer to the <TT>idraw</TT> section for more details. 

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<A NAME="Heading25<FONT COLOR="#000077"><B>CAUTION:</B> </FONT>Changes made

	with the Examine tool and Relate tool can be undone. 

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<P>The Show Glue tool shows HGlue components with horizontal strips and VGlue components

with vertical strips. Showing Glue components with strips makes the structure associated

with the interface more apparent.</P>

<P>The Hidden Glue tool shows HGlue and VGlue components with their background color.

This is useful when the actual appearance of the interface is desired.</P>

<P>The Natural Size tool shows the selected interface components in their natural

form, similar to the way they are displayed initially when the generated interfaces

are executed.

<CENTER>

<H4><A NAME="Heading26<FONT COLOR="#000077">ibuilds Pull-Down Menus</FONT></H4>

</CENTER>

<P>The pull-down menus File, Edit Composition, Border, FgColor, BgColor, Align, and

View lie across the third row. They contain commands that are executed by pulling

down the menu and releasing the mouse button on the command, or by typing the character

associated with the command.</P>

<P>The File menu contains the following commands to operate on files:



<UL>

	<LI>The New command destroys the current interface and replaces it with an unnamed

	blank interface.

	<P>

	<LI>The Revert command rereads the current interface, destroying any unsaved changes.

	<P>

	<LI>The Open command specifies an existing interface file to edit through a FileChooser,

	which lets you browse the file system easily.

	<P>

	<LI>The Save As command saves the current interface in a file with a specific name.

	<P>

	<LI>The Save command saves the current interface in the file from which it came.

</UL>



<CENTER>

<H4><A NAME="Heading27<FONT COLOR="#000077">Generating Source Files</FONT></H4>

</CENTER>

<P>The Generate button generates code for the interfaces in <TT>ibuild</TT>. A sequence

of dialog boxes pops up to let users check off files that they don't want to be overwritten.

The generated files include sets of subclass files and support files. Subclass files

have class name suffixes, and support files have filename postfixes. For instance,

the filename of a session of <TT>ibuild</TT> is <TT>dialogBox</TT>, and the top-level

MonoScene object that drives the interface is <TT>DialogBox</TT>.</P>

<P>Support files generated include the following:



<UL>

	<LI><TT>dialogBox-props</TT>

	<P>

	<LI><TT>dialogBoxmake</TT>

	<P>

	<LI><TT>dialogBox-imake</TT>

	<P>

	<LI><TT>dialogBox-main.c</TT>

	<P>

	<LI><TT>dialogBox-imake</TT>

	<P>

	<LI><TT>dialogBox-make</TT>

</UL>



<P>For each MonoScene component in <TT>ibuild</TT>, a set of subclass files is generated.

In this case, they include the following:



<UL>

	<LI><TT>DialogBox.c</TT>

	<P>

	<LI><TT>DialogBox.h</TT>

	<P>

	<LI><TT>DialogBox-core.c</TT>

	<P>

	<LI><TT>DialogBox-core.h</TT>

</UL>



<P>When you regenerate the code for an application, you are asked in a dialog box

whether you want to regenerate these files. As a general rule, all the default files

that <TT>ibuild</TT> recommends by checking in their dialog box should be overwritten.</P>

<P>The <TT>dialogBox-props</TT> file contains Interviews properties for customization.

Rewrite this file whenever you regenerate.</P>

<P>The <TT>dialogBox-main.c</TT> file contains a prototypical main routine to drive

the interface. Rewrite this file whenever you regenerate.</P>

<P>The <TT>DialogBox-core.c</TT> file encapsulates all information about the appearance

of the interface. The protected member variables are declared in this file.</P>

<P>The <TT>DialogBox-core.h</TT> file describes what objects are exported to the

subclass objects (such as DialogBox) for manipulation. This file is, and should be,

overwritten whenever you regenerate a new application using <TT>ibuild</TT>.</P>

<P>The <TT>DialogBox.h</TT> and <TT>DialogBox.c</TT> files enable users to implement

application-specific interfaces. When you are regenerating code from an <TT>ibuild</TT>

session, you are asked whether you want to overwrite these files. If you already

have application-dependent code in these files, you don't want to overwrite these