To complete the examination of building windows using the SWT you must look at the final element that end users expect to see in a well-designed window—the toolbar. A toolbar is a row of buttons that appears below the menu and above the working area of the window to allow one-click access to the most commonly used functionality of your application. If your application supports the use of a menu—and almost every application will—it can benefit from the use of a toolbar.
Toolbar buttons can have a text label, an image, or both; the use of images that provide a hint about the functionality of the button is a nice touch. If you examine other applications running on your chosen platform, you will likely find that the use of images, rather than text, is the norm. Toolbar buttons also often make use of pop-up Help text that appears whenever the mouse hovers over the button.
SWT provides two classes that you use in toolbar creation—the
ToolBar and
ToolItem
classes. These classes are part of the
org.eclipse.swt.widgets
package. The
Image
class, located in the
org.eclipse.swt.graphics package, is also used to
load and specify an icon or bitmap for use as a toolbar
button’s image, just as it specified a window icon
for your shell back in Chapter 2.
Creating
toolbars
is much like creating menus. Simply create an instance of the
ToolBar class to serve as the container for the
individual buttons, which are represented by instances of the
ToolItem class.
Once you are armed with a list of buttons that you wish to appear on the toolbar, and you have acquired or developed images for those buttons, you are ready to begin development of your toolbar.
Note
Toolbars should be thoughtfully designed prior to development. There is only a small amount of space at the top of the window, so putting some thought into these decisions ahead of time (and/or talking it over with the intended user base) can save hours of programming time down the road.
First, create the toolbar itself—an instance of the
ToolBar class:
final ToolBar bar = new ToolBar(s, SWT.HORIZONTAL);
This single line of code creates an instance of
ToolBar and attaches it to a shell, referenced by
the variable s.
Next, set the size and location of the toolbar:
bar.setSize(300, 65); bar.setLocation(0,0);
The first line sets the toolbar’s width and height. Generally, you should specify a width equal to the window’s width and a height that is of sufficient size to accommodate the buttons that will be placed on the toolbar. This, of course, will depend on the size of images you plan to use for those buttons, so once again planning before coding is required.
The second line sets the X and Y coordinates of the toolbar’s upper left-hand corner relative to the working area of the window. Generally, if you want the toolbar to be positioned directly below the menu, set the toolbar’s location to 0, 0. If you’re using a vertical toolbar, set the parameters to values that would make the toolbar position itself along either the left or right of the window. The right side position can be calculated by subtracting the width of the toolbar from the width of the window
First, create the toolbar itself—an instance of the
ToolBar class:
final ToolBar bar = new ToolBar(s, SWT.HORIZONTAL);
This single line of code creates an instance of
ToolBar and attaches it to a shell, referenced by
the variable s.
Next, set the size and location of the toolbar:
bar.setSize(300, 65); bar.setLocation(0,0);
The first line sets the toolbar’s width and height. Generally, you should specify a width equal to the window’s width and a height that is of sufficient size to accommodate the buttons that will be placed on the toolbar. This, of course, will depend on the size of images you plan to use for those buttons, so once again planning before coding is required.
The second line sets the X and Y coordinates of the toolbar’s upper left-hand corner relative to the working area of the window. Generally, if you want the toolbar to be positioned directly below the menu, set the toolbar’s location to 0, 0. If you’re using a vertical toolbar, set the parameters to values that would make the toolbar position itself along either the left or right of the window. The right side position can be calculated by subtracting the width of the toolbar from the width of the window
using other styles for your toolbar? You can use five styles with the
ToolBar class.
First, create the toolbar itself—an instance of the
ToolBar
class:
final ToolBar bar = new ToolBar(s, SWT.HORIZONTAL);
This single line of code creates an instance of
ToolBar and attaches it to a
shell, referenced by the variable
s.
Next, set the size and location of the toolbar:
bar.setSize(300, 65); bar.setLocation(0,0);
The first line sets the toolbar’s width and height. Generally, you should specify a width equal to the window’s width and a height that is of sufficient size to accommodate the buttons that will be placed on the toolbar. This, of course, will depend on the size of images you plan to use for those buttons, so once again planning before coding is required.
The second line sets the X and Y coordinates of the toolbar’s upper left-hand corner relative to the working area of the window. Generally, if you want the toolbar to be positioned directly below the menu, set the toolbar’s location to 0, 0. If you’re using a vertical toolbar, set the parameters to values that would make the toolbar position itself along either the left or right of the window. The right side position can be calculated by subtracting the width of the toolbar from the width of the window
using other
styles for your toolbar? You can use
five styles with the ToolBar class.
-
SWT.FLAT Creates a non-3D toolbar.
-
SWT.HORIZONTAL Positions the toolbar at the top of the window, below the menu bar.
-
SWT.WRAP Causes the toolbar item text to wrap across multiple lines.
-
SWT.RIGHT Causes the text on toolbar items to be right-justified (appearing to the right of any image) .
-
SWT.VERTICAL Positions the toolbar vertically along either side of the window, depending upon the parameters passed to the
setLocation()method.
Some styles—for example, the RIGHT and
WRAP styles—can be combined to achive a
desire effect.
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