org.gnu.gtk

Class ProgressBar

public class ProgressBar extends Progress

The ProgressBar is typically used to display the progress of a long running operation. It provides a visual clue that processing is underway. The ProgressBar can be used in two different modes: percentage mode and activity mode.

When an application can determine how much work needs to take place (e.g. read a fixed number of bytes from a file) and can monitor its progress, it can use the ProgressBar in percentage mode and the user sees a growing bar indicating the percentage of the work that has been completed. In this mode, the application is required to call ProgressBar periodically to update the progress bar.

When an application has no accurate way of knowing the amount of work to do, it can use the ProgressBar in activity mode, which shows activity by a block moving back and forth within the progress area. In this mode, the application is required to call pulse periodically to update the progress bar.

There is quite a bit of flexibility provided to control the appearance of the ProgressBar. Functions are provided to control the orientation of the bar, optional text can be displayed along with the bar, and the step size used in activity mode can be set.

Constructor Summary
ProgressBar()
Constructs a new ProgressBar widget
ProgressBar(Handle handle)
Construct a new ProgressBar passing a handle to a native widget resource.
Method Summary
EllipsizeModegetEllipsize()
Returns the ellipsizing position.
doublegetFraction()
Returns the current value of the display.
static ProgressBargetProgressBar(Handle handle)
Internal static factory method to be used by Java-Gnome only.
static TypegetType()
Retrieve the runtime type used by the GLib library.
voidpulse()
Indicates that some progress is made, but you don't know how much.
voidsetEllipsize(EllipsizeMode mode)
Sets the mode used to ellipsize (add an ellipsis: "...") the text if there is not enough space to render the entire string.
voidsetFraction(double fraction)
Causes the progress bar to "fill in" the given fraction of the bar.
voidsetOrientation(ProgressBarOrientation orientation)
Causes the progress bar to switch to a different orientation (left-to-right, right-to-left, top-to-bottom, or bottom-to-top).
voidsetPulseStep(double fraction)
Sets the fraction of total progress bar length to move the bouncing block for each call to pulse.
voidsetText(String text)
Causes the given text to appear superimposed on the progress bar.

Constructor Detail

ProgressBar

public ProgressBar()
Constructs a new ProgressBar widget

ProgressBar

public ProgressBar(Handle handle)
Construct a new ProgressBar passing a handle to a native widget resource.

Parameters: handle The handle to the native ProgressBar.

Method Detail

getEllipsize

public EllipsizeMode getEllipsize()
Returns the ellipsizing position.

Since: 2.6

getFraction

public double getFraction()
Returns the current value of the display. This value will be returned as a value between 0.0 and 1.0.

getProgressBar

public static ProgressBar getProgressBar(Handle handle)
Internal static factory method to be used by Java-Gnome only.

getType

public static Type getType()
Retrieve the runtime type used by the GLib library.

pulse

public void pulse()
Indicates that some progress is made, but you don't know how much. Causes the progress bar to enter "activity mode," where a block bounces back and forth. Each call to pulse() causes the block to move by a little bit (the amount of movement per pulse is determined by ProgressBar).

setEllipsize

public void setEllipsize(EllipsizeMode mode)
Sets the mode used to ellipsize (add an ellipsis: "...") the text if there is not enough space to render the entire string.

Since: 2.6

setFraction

public void setFraction(double fraction)
Causes the progress bar to "fill in" the given fraction of the bar. The fraction should be between 0.0 and 1.0, inclusive. Any value less than 0.0 will be considered as 0.0, and any value bigger than 1.0 will be considered as 1.0. The reason why this is done is because Java has a strict implementation of doubles and floats, and sometimes that can cause unwanted rounding of numbers.

For example, you may think '0.9 + 0.1 = 1.0', but the fact is that could actually result in 1.00001, or anything like that.

Parameters: fraction The fraction of the progress bar which should be filled in

Throws: IllegalArgumentException

setOrientation

public void setOrientation(ProgressBarOrientation orientation)
Causes the progress bar to switch to a different orientation (left-to-right, right-to-left, top-to-bottom, or bottom-to-top).

See Also: ProgressBarOrientation

setPulseStep

public void setPulseStep(double fraction)
Sets the fraction of total progress bar length to move the bouncing block for each call to pulse.

Parameters: fraction fraction between 0.0 and 1.0

setText

public void setText(String text)
Causes the given text to appear superimposed on the progress bar.

Parameters: text The string to appear on the progress bar