Eclipse Platform
Pre-release 3.0

org.eclipse.debug.core.model
Interface IWatchExpression

All Superinterfaces:
IAdaptable, IDebugElement, IErrorReportingExpression, IExpression

public interface IWatchExpression
extends IErrorReportingExpression

A watch expression is an expression that is evaluated in the context of a specific stack frame, thread, debug target, process, or launch. Generally, a watch expression is a snippet of code that is evaluated each time a debug target suspends, or when a user provides a context for an evaluation by selecting a debug target or thread. An expression updates its value when it is provided with a context in which it can perform an evaluation.

Since:
3.0

Method Summary
 void evaluate()
          Causes this expression to update its value based on the last context set for this watch expression.
 boolean isEnabled()
          Returns whether this expression is enabled.
 boolean isObsolete()
          Returns whether this expression's value is obsolete.
 boolean isPending()
          Returns whether the result of this watch expression is pending.
 void setEnabled(boolean enabled)
          Sets this expression's enabled state.
 void setExpressionContext(IDebugElement context)
          Sets the context for this watch expression, or null if none.
 void setExpressionText(String expressionText)
          Sets this watch expression's snippet of code.
 
Methods inherited from interface org.eclipse.debug.core.model.IErrorReportingExpression
getErrorMessages, hasErrors
 
Methods inherited from interface org.eclipse.debug.core.model.IExpression
dispose, getDebugTarget, getExpressionText, getValue
 
Methods inherited from interface org.eclipse.debug.core.model.IDebugElement
getLaunch, getModelIdentifier
 
Methods inherited from interface org.eclipse.core.runtime.IAdaptable
getAdapter
 

Method Detail

evaluate

public void evaluate()
Causes this expression to update its value based on the last context set for this watch expression. When the value update is complete, a debug change event is fired. A watch expression can be asked to evaluate even when it is disabled.


setExpressionContext

public void setExpressionContext(IDebugElement context)
Sets the context for this watch expression, or null if none. If the given context is valid for this expression, this expression may update its value. When the value update is complete, a debug change event is fired. When null is specified as a context, this expression may choose to retain its previous value.

The context is usually one of (but not limited to):

Parameters:
context - context in which to update this expression's value, or null if none

setExpressionText

public void setExpressionText(String expressionText)
Sets this watch expression's snippet of code. This method causes the new snippet to be evaluated immediately in the expression's last context.

Parameters:
expressionText - the snippet which will be evaluated

isPending

public boolean isPending()
Returns whether the result of this watch expression is pending. An expression is pending if an evaluation has been requested, but the value has not yet been returned.

Returns:
whether this expression's result is pending

isEnabled

public boolean isEnabled()
Returns whether this expression is enabled. An enabled expression will update its value. A disabled expression will not.

Returns:
whether this expression is enabled

setEnabled

public void setEnabled(boolean enabled)
Sets this expression's enabled state. This method causes the new snippet to be evaluated immediately in the expression's last context.

Parameters:
enabled - whether this expression should be enabled

isObsolete

public boolean isObsolete()
Returns whether this expression's value is obsolete. An expression is obsolete if it has a value, is disabled, and then has a new context set.

Returns:
whether this expression's value is obsolete

Eclipse Platform
Pre-release 3.0

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