Activities

Identifier:

Since:

3.0

Description:

The org.eclipse.ui.activities extension point is used to declare activities and associated elements. Activities are used by the platform to filter certain plugin contributions from the users view until such a time that they express interest in them. This allows Eclipse to grow dynamically based on the usage pattern of a user.

Configuration Markup:

<!ELEMENT extension (activity , activityRequirementBinding , activityPatternBinding , category , categoryActivityBinding , defaultEnablement)*>

<!ATTLIST extension

id    CDATA #IMPLIED

name  CDATA #IMPLIED

point CDATA #REQUIRED

• id - an optional identifier of the extension instance
• name - an optional name of the extension instance
• point - a fully qualified identifier of the target extension point

<!ELEMENT activity (enabledWhen?)>

<!ATTLIST activity

description CDATA #IMPLIED

id          CDATA #REQUIRED

name        CDATA #REQUIRED

This element is used to define activities. If more than one of these elements exist with the same id attribute, only the last declared element (in order of reading the registry) is considered valid.

• description - a translatable short description of this activity for display in the UI
• id - the unique identifier of this activity
• name - the translatable name of this activity for display in the UI

<!ELEMENT activityRequirementBinding EMPTY>

<!ATTLIST activityRequirementBinding

requiredActivityId IDREF #REQUIRED

activityId         IDREF #REQUIRED

This element allows one to bind activities to activities. The relationship is such that if the activityId is ever enabled then the requiredActivityId is enabled as well.

• requiredActivityId - the unique identifier of required activity to bind
• activityId - the unique identifier of the activity to bind

<!ELEMENT activityPatternBinding EMPTY>

<!ATTLIST activityPatternBinding

activityId        IDREF #REQUIRED

pattern           CDATA #REQUIRED

isEqualityPattern (true | false)

This element allows one to bind activities to patterns.

• activityId - the unique identifier of the activity to bind
• pattern - the pattern to be bound. Patterns are regular expressions which match unique identifiers. Please see the Java documentation for java.util.regex.Pattern for further details.
• isEqualityPattern - if the pattern should be considered "as is". This is an optional attribute and if ommited the value is false If this is false the pattern string will be compiled into a regular expression when determining whether or not a given identifier matches the pattern. If this is true, a direct equality comparison is performed instead. Since 3.4

<!ELEMENT category EMPTY>

<!ATTLIST category

description CDATA #IMPLIED

id          CDATA #REQUIRED

name        CDATA #REQUIRED

This element is used to define categories. If more than one of these elements exist with the same id attribute, only the last declared element (in order of reading the registry) is considered valid.

• description - a translatable short description of this category for display in the UI
• id - the unique identifier of this category
• name - the translatable name of this category for display in the UI

<!ELEMENT categoryActivityBinding EMPTY>

<!ATTLIST categoryActivityBinding

activityId IDREF #REQUIRED

categoryId IDREF #REQUIRED

This element allows one to bind categories to activities.

• activityId - the unique identifier of the activity to bind
• categoryId - the unique identifier of the category to bind

<!ELEMENT defaultEnablement EMPTY>

<!ATTLIST defaultEnablement

id IDREF #REQUIRED

This element allows one to specify that a given activity should be enabled by default.

• id - the unique identifier of the activity

<!ELEMENT enabledWhen (not | and | or | instanceof | test | systemTest | equals | count | with | resolve | adapt | iterate | reference)>

<!ELEMENT enablement (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

A generic root element. The element can be used inside an extension point to define its enablement expression. The children of an enablement expression are combined using the "and" operator.

<!ELEMENT not (not | and | or | instanceof | test | systemTest | equals | count | with | resolve | adapt | iterate | reference)>

This element represents a NOT operation on the result of evaluating its sub-element expression.

<!ELEMENT and (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

This element represents an AND operation on the result of evaluating all its sub-elements expressions.

<!ELEMENT or (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

This element represent an OR operation on the result of evaluating all its sub-element expressions.

<!ELEMENT instanceof EMPTY>

<!ATTLIST instanceof

value CDATA #REQUIRED

This element is used to perform an instanceof check of the object in focus. The expression returns EvaluationResult.TRUE if the object's type is a sub type of the type specified by the attribute value. Otherwise EvaluationResult.FALSE is returned.

• value - a fully qualified name of a class or interface.

<!ELEMENT test EMPTY>

<!ATTLIST test

property              CDATA #REQUIRED

args                  CDATA #IMPLIED

value                 CDATA #IMPLIED

forcePluginActivation (true | false)

This element is used to evaluate the property state of the object in focus. The set of testable properties can be extended using the org.eclipse.core.expressions.propertyTesters extension point. The test expression returns EvaluationResult.NOT_LOADED if the property tester doing the actual testing isn't loaded yet and the attribute forcePluginActivation is set to false. If forcePluginActivation is set to true and the evaluation context used to evaluate this expression support plug-in activation then evaluating the property will result in activating the plug-in defining the tester.

• property - the name of an object's property to test.
• args - additional arguments passed to the property tester. Multiple arguments are separated by commas. Each individual argument is converted into a Java base type using the same rules as defined for the value attribute of the test expression.
• value - the expected value of the property. Can be omitted if the property is a boolean property. The test expression is supposed to return EvaluationResult.TRUE if the property matches the value and EvaluationResult.FALSE otherwise. The value attribute is converted into a Java base type using the following rules:
  • the string "true" is converted into Boolean.TRUE
  • the string "false" is converted into Boolean.FALSE
  • if the string contains a dot then the interpreter tries to convert the value into a Float object. If this fails the string is treated as a java.lang.String
  • if the string only consists of numbers then the interpreter converts the value into an Integer object.
  • in all other cases the string is treated as a java.lang.String
  • the conversion of the string into a Boolean, Float, or Integer can be suppressed by surrounding the string with single quotes. For example, the attribute value="'true'" is converted into the string "true"
• forcePluginActivation - a flag indicating whether the plug-in contributing the property tester should be loaded if necessary. As such, this flag should be used judiciously, in order to avoid unnecessary plug-in activations. Most clients should avoid setting this flag to true. This flag is only honored if the evaluation context used to evaluate this expression allows plug-in activation. Otherwise the flag is ignored and no plug-in loading takes place.

<!ELEMENT systemTest EMPTY>

<!ATTLIST systemTest

property CDATA #REQUIRED

value    CDATA #REQUIRED

Tests a system property by calling the System.getProperty method and compares the result with the value specified through the value attribute.

• property - the name of an system property to test.
• value - the expected value of the property. The value is interpreted as a string value.

<!ELEMENT equals EMPTY>

<!ATTLIST equals

value CDATA #REQUIRED

This element is used to perform an equals check of the object in focus. The expression returns EvaluationResult.TRUE if the object is equal to the value provided by the attribute value. Otherwise EvaluationResult.FALSE is returned.

• value - the expected value. The value provided as a string is converted into a Java base type using the same rules as for the value attribute of the test expression.

<!ELEMENT count EMPTY>

<!ATTLIST count

value CDATA #REQUIRED

This element is used to test the number of elements in a collection.

• value - an expression to specify the number of elements in a list. Following wildcard characters can be used:

  *

  any number of elements

  ?

  no elements or one element

  +

  one or more elements

  !

  no elements

  -N)

  less than N elements

  (N-

  greater than N elements

  integer value

  the list must contain the exact number of elements

<!ELEMENT with (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST with

variable CDATA #REQUIRED

This element changes the object to be inspected for all its child element to the object referenced by the given variable. If the variable can not be resolved then the expression will throw an ExpressionException when evaluating it. The children of a with expression are combined using the "and" operator.

• variable - the name of the variable to be used for further inspection. It is up to the evaluator of an extension point to provide the variable in the variable pool.

<!ELEMENT resolve (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST resolve

variable CDATA #REQUIRED

args     CDATA #IMPLIED

This element changes the object to be inspected for all its child element to the object referenced by the given variable. If the variable can not be resolved then the expression will throw an ExpressionException when evaluating it. The children of a resolve expression are combined using the "and" operator.

• variable - the name of the variable to be resolved. This variable is then used as the object in focus for child element evaluation. It is up to the evaluator of an extension point to provide a corresponding variable resolver (see IVariableResolver) through the evaluation context passed to the root expression element when evaluating the expression.
• args - additional arguments passed to the variable resolver. Multiple arguments are separated by commas. Each individual argument is converted into a Java base type using the same rules as defined for the value attribute of the test expression.

<!ELEMENT adapt (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST adapt

type CDATA #REQUIRED

This element is used to adapt the object in focus to the type specified by the attribute type. The expression returns EvaluationResult.NOT_LOADED if either the adapter or the type referenced isn't loaded yet. It throws an ExpressionException during evaluation if the type name doesn't exist at all. The children of an adapt expression are combined using the "and" operator.

• type - the type to which the object in focus is to be adapted.

<!ELEMENT iterate (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST iterate

operator (or|and)

ifEmpty  (true | false)

This element is used to iterate over a variable that is of type java.util.Collection, or a variable that adapts to org.eclipse.core.expressions.IIterable. If the object in focus is not one of the above then a CoreException with an ExpressionStatus will be thrown while evaluating the expression. The child expressions of an iterate expression are combined using the "and" operator.

• operator - either "and" or "or". The operator defines how the results of all the child expressions applied to each child of the Collection or IIterable will be combined and what (if any) short circuit evaluation will be used. If not specified, "and" will be used.
• ifEmpty - the value returned from the "iterate" expression if the collection is empty. If not specified then EvaluationResult.TRUE is returned when the operator equals "and" and EvaluationResult.FALSE is returned if the operator equals "or".

<!ELEMENT reference EMPTY>

<!ATTLIST reference

definitionId IDREF #REQUIRED

This element is used to reference an expression from the org.eclipse.core.expressions.definitions extension point. The expression definition will be evaluated within the current expression element using the current evaluation context.

• definitionId - The unique id of an expression from org.eclipse.core.expressions.definitions.

<!ELEMENT enablement (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

A generic root element. The element can be used inside an extension point to define its enablement expression. The children of an enablement expression are combined using the "and" operator.

<!ELEMENT not (not | and | or | instanceof | test | systemTest | equals | count | with | resolve | adapt | iterate | reference)>

This element represents a NOT operation on the result of evaluating its sub-element expression.

<!ELEMENT and (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

This element represents an AND operation on the result of evaluating all its sub-elements expressions.

<!ELEMENT or (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

This element represent an OR operation on the result of evaluating all its sub-element expressions.

<!ELEMENT instanceof EMPTY>

<!ATTLIST instanceof

value CDATA #REQUIRED

This element is used to perform an instanceof check of the object in focus. The expression returns EvaluationResult.TRUE if the object's type is a sub type of the type specified by the attribute value. Otherwise EvaluationResult.FALSE is returned.

• value - a fully qualified name of a class or interface.

<!ELEMENT test EMPTY>

<!ATTLIST test

property              CDATA #REQUIRED

args                  CDATA #IMPLIED

value                 CDATA #IMPLIED

forcePluginActivation (true | false)

This element is used to evaluate the property state of the object in focus. The set of testable properties can be extended using the org.eclipse.core.expressions.propertyTesters extension point. The test expression returns EvaluationResult.NOT_LOADED if the property tester doing the actual testing isn't loaded yet and the attribute forcePluginActivation is set to false. If forcePluginActivation is set to true and the evaluation context used to evaluate this expression support plug-in activation then evaluating the property will result in activating the plug-in defining the tester.

• property - the name of an object's property to test.
• args - additional arguments passed to the property tester. Multiple arguments are separated by commas. Each individual argument is converted into a Java base type using the same rules as defined for the value attribute of the test expression.
• value - the expected value of the property. Can be omitted if the property is a boolean property. The test expression is supposed to return EvaluationResult.TRUE if the property matches the value and EvaluationResult.FALSE otherwise. The value attribute is converted into a Java base type using the following rules:
  • the string "true" is converted into Boolean.TRUE
  • the string "false" is converted into Boolean.FALSE
  • if the string contains a dot then the interpreter tries to convert the value into a Float object. If this fails the string is treated as a java.lang.String
  • if the string only consists of numbers then the interpreter converts the value into an Integer object.
  • in all other cases the string is treated as a java.lang.String
  • the conversion of the string into a Boolean, Float, or Integer can be suppressed by surrounding the string with single quotes. For example, the attribute value="'true'" is converted into the string "true"
• forcePluginActivation - a flag indicating whether the plug-in contributing the property tester should be loaded if necessary. As such, this flag should be used judiciously, in order to avoid unnecessary plug-in activations. Most clients should avoid setting this flag to true. This flag is only honored if the evaluation context used to evaluate this expression allows plug-in activation. Otherwise the flag is ignored and no plug-in loading takes place.

<!ELEMENT systemTest EMPTY>

<!ATTLIST systemTest

property CDATA #REQUIRED

value    CDATA #REQUIRED

Tests a system property by calling the System.getProperty method and compares the result with the value specified through the value attribute.

• property - the name of an system property to test.
• value - the expected value of the property. The value is interpreted as a string value.

<!ELEMENT equals EMPTY>

<!ATTLIST equals

value CDATA #REQUIRED

This element is used to perform an equals check of the object in focus. The expression returns EvaluationResult.TRUE if the object is equal to the value provided by the attribute value. Otherwise EvaluationResult.FALSE is returned.

• value - the expected value. The value provided as a string is converted into a Java base type using the same rules as for the value attribute of the test expression.

<!ELEMENT count EMPTY>

<!ATTLIST count

value CDATA #REQUIRED

This element is used to test the number of elements in a collection.

• value - an expression to specify the number of elements in a list. Following wildcard characters can be used:

  *

  any number of elements

  ?

  no elements or one element

  +

  one or more elements

  !

  no elements

  -N)

  less than N elements

  (N-

  greater than N elements

  integer value

  the list must contain the exact number of elements

<!ELEMENT with (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST with

variable CDATA #REQUIRED

This element changes the object to be inspected for all its child element to the object referenced by the given variable. If the variable can not be resolved then the expression will throw an ExpressionException when evaluating it. The children of a with expression are combined using the "and" operator.

• variable - the name of the variable to be used for further inspection. It is up to the evaluator of an extension point to provide the variable in the variable pool.

<!ELEMENT resolve (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST resolve

variable CDATA #REQUIRED

args     CDATA #IMPLIED

This element changes the object to be inspected for all its child element to the object referenced by the given variable. If the variable can not be resolved then the expression will throw an ExpressionException when evaluating it. The children of a resolve expression are combined using the "and" operator.

• variable - the name of the variable to be resolved. This variable is then used as the object in focus for child element evaluation. It is up to the evaluator of an extension point to provide a corresponding variable resolver (see IVariableResolver) through the evaluation context passed to the root expression element when evaluating the expression.
• args - additional arguments passed to the variable resolver. Multiple arguments are separated by commas. Each individual argument is converted into a Java base type using the same rules as defined for the value attribute of the test expression.

<!ELEMENT adapt (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST adapt

type CDATA #REQUIRED

This element is used to adapt the object in focus to the type specified by the attribute type. The expression returns EvaluationResult.NOT_LOADED if either the adapter or the type referenced isn't loaded yet. It throws an ExpressionException during evaluation if the type name doesn't exist at all. The children of an adapt expression are combined using the "and" operator.

• type - the type to which the object in focus is to be adapted.

<!ELEMENT iterate (not , and , or , instanceof , test , systemTest , equals , count , with , resolve , adapt , iterate , reference)*>

<!ATTLIST iterate

operator (or|and)

ifEmpty  (true | false)

This element is used to iterate over a variable that is of type java.util.Collection, or a variable that adapts to org.eclipse.core.expressions.IIterable. If the object in focus is not one of the above then a CoreException with an ExpressionStatus will be thrown while evaluating the expression. The child expressions of an iterate expression are combined using the "and" operator.

• operator - either "and" or "or". The operator defines how the results of all the child expressions applied to each child of the Collection or IIterable will be combined and what (if any) short circuit evaluation will be used. If not specified, "and" will be used.
• ifEmpty - the value returned from the "iterate" expression if the collection is empty. If not specified then EvaluationResult.TRUE is returned when the operator equals "and" and EvaluationResult.FALSE is returned if the operator equals "or".

<!ELEMENT reference EMPTY>

<!ATTLIST reference

definitionId IDREF #REQUIRED

This element is used to reference an expression from the org.eclipse.core.expressions.definitions extension point. The expression definition will be evaluated within the current expression element using the current evaluation context.

• definitionId - The unique id of an expression from org.eclipse.core.expressions.definitions.

Examples:

 <extension point="org.eclipse.ui.activities">
  <activity id="com.xyz.Activity"
      description="Filters contributions from com.xyz"
   name="My Activity" />

  <activity id="com.xyz.OtherActivity"
      description="Filters other contributions from com.xyz"
   name="My Other Activity" />
  <!-- other activity requires activity -->  
  <activityRequirementBinding activityId="com.xyz.OtherActivity"
   requiredActivityId="com.xyz.Activity" />
  <category id="com.xyz.Category"
   description="com.xyz Activities"
   name="My Category" />
   
     <!-- put the activity in the category -->
  <categoryActivityBinding activityId="com.xyz.Activity"
   categoryId="com.xyz.Category" />
   
     <!-- bind all contributions from plugin com.xyz -->
  <activityPatternBinding id="com.xyz.Activity"
   pattern="com\.xyz/.*" />
  
  <!-- bind my.contribution from plugin com.xyz.other -->
  <activityPatternBinding id="com.xyz.OtherActivity"
   pattern="com\.xyz\.other/my.contribution" />
   
  <!-- the same, but not with a regular expression, since the pattern
          should match the id exactly anyway -->
  <activityPatternBinding id="com.xyz.OtherActivity"
   isEqualityPattern="true"
   pattern="com.xyz.other/my.contribution" />
   
  <!-- our activity should be enabled by default -->
  <defaultEnablement id="com.xyz.Activity" />  
 </extension>

API Information:

There is currently no public API for declaring activities or associated elements other than this extension point. The state of activities in the workbench is accessible via org.eclipse.ui.IWorkbench.getActivitySupport(). From here you may query and update the set of currently enabled activities.

Supplied Implementation:

Copyright (c) 2000, 2005 IBM Corporation and others.
All rights reserved. This program and the accompanying materials are made available under the terms of the Eclipse Public License v1.0 which accompanies this distribution, and is available at http://www.eclipse.org/legal/epl-v10.html