CursorTreeAdapter
abstract class CursorTreeAdapter : BaseExpandableListAdapter, Filterable
Known Indirect Subclasses
SimpleCursorTreeAdapter |
An easy adapter to map columns from a cursor to TextViews or ImageViews defined in an XML file.
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An adapter that exposes data from a series of Cursor
s to an ExpandableListView
widget. The top-level Cursor
(that is given in the constructor) exposes the groups, while subsequent Cursor
s returned from getChildrenCursor(android.database.Cursor)
expose children within a particular group. The Cursors must include a column named "_id" or this class will not work.
Summary
Public constructors |
Constructor.
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Constructor.
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Protected methods |
abstract Unit |
Bind an existing view to the child data pointed to by cursor
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abstract Unit |
Bind an existing view to the group data pointed to by cursor.
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abstract Cursor! |
Gets the Cursor for the children at the given group.
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abstract View! |
Makes a new child view to hold the data pointed to by cursor.
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abstract View! |
Makes a new group view to hold the group data pointed to by cursor.
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Inherited functions |
From class BaseExpandableListAdapter
Boolean |
areAllItemsEnabled()
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Int |
getChildType(groupPosition: Int, childPosition: Int)
Get the type of child View that will be created by android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup) for the specified child item.
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Int |
getChildTypeCount()
Returns the number of types of child Views that will be created by android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup) . Each type represents a set of views that can be converted in android.widget.ExpandableListAdapter#getChildView(int, int, boolean, View, ViewGroup) , for any group. If the adapter always returns the same type of View for all child items, this method should return 1.
This method will only be called when the adapter is set on the AdapterView .
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Long |
getCombinedChildId(groupId: Long, childId: Long)
Override this method if you foresee a clash in IDs based on this scheme:
Base implementation returns a long:
bit 0: Whether this ID points to a child (unset) or group (set), so for this method this bit will be 1.
bit 1-31: Lower 31 bits of the groupId
bit 32-63: Lower 32 bits of the childId.
Gets an ID for a child that is unique across any item (either group or child) that is in this list. Expandable lists require each item (group or child) to have a unique ID among all children and groups in the list. This method is responsible for returning that unique ID given a child's ID and its group's ID. Furthermore, if hasStableIds() is true, the returned ID must be stable as well.
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Long |
getCombinedGroupId(groupId: Long)
Override this method if you foresee a clash in IDs based on this scheme:
Base implementation returns a long:
bit 0: Whether this ID points to a child (unset) or group (set), so for this method this bit will be 0.
bit 1-31: Lower 31 bits of the groupId
bit 32-63: Lower 32 bits of the childId.
Gets an ID for a group that is unique across any item (either group or child) that is in this list. Expandable lists require each item (group or child) to have a unique ID among all children and groups in the list. This method is responsible for returning that unique ID given a group's ID. Furthermore, if hasStableIds() is true, the returned ID must be stable as well.
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Int |
getGroupType(groupPosition: Int)
Get the type of group View that will be created by android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup) . for the specified group item.
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Int |
getGroupTypeCount()
Returns the number of types of group Views that will be created by android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup) . Each type represents a set of views that can be converted in android.widget.ExpandableListAdapter#getGroupView(int, boolean, View, ViewGroup) . If the adapter always returns the same type of View for all group items, this method should return 1.
This method will only be called when the adapter is set on the AdapterView .
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Boolean |
isEmpty()
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Unit |
onGroupExpanded(groupPosition: Int)
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Unit |
registerDataSetObserver(observer: DataSetObserver!)
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Unit |
unregisterDataSetObserver(observer: DataSetObserver!)
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From class ExpandableListAdapter
Any! |
getChild(groupPosition: Int, childPosition: Int)
Gets the data associated with the given child within the given group.
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Long |
getChildId(groupPosition: Int, childPosition: Int)
Gets the ID for the given child within the given group. This ID must be unique across all children within the group. The combined ID (see getCombinedChildId(long,long) ) must be unique across ALL items (groups and all children).
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View! |
getChildView(groupPosition: Int, childPosition: Int, isLastChild: Boolean, convertView: View!, parent: ViewGroup!)
Gets a View that displays the data for the given child within the given group.
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Int |
getChildrenCount(groupPosition: Int)
Gets the number of children in a specified group.
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Any! |
getGroup(groupPosition: Int)
Gets the data associated with the given group.
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Int |
getGroupCount()
Gets the number of groups.
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Long |
getGroupId(groupPosition: Int)
Gets the ID for the group at the given position. This group ID must be unique across groups. The combined ID (see getCombinedGroupId(long) ) must be unique across ALL items (groups and all children).
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View! |
getGroupView(groupPosition: Int, isExpanded: Boolean, convertView: View!, parent: ViewGroup!)
Gets a View that displays the given group. This View is only for the group--the Views for the group's children will be fetched using getChildView(int,int,boolean,android.view.View,android.view.ViewGroup) .
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Boolean |
hasStableIds()
Indicates whether the child and group IDs are stable across changes to the underlying data.
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Boolean |
isChildSelectable(groupPosition: Int, childPosition: Int)
Whether the child at the specified position is selectable.
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Public constructors
CursorTreeAdapter
CursorTreeAdapter(
cursor: Cursor!,
context: Context!)
Constructor. The adapter will call Cursor.requery()
on the cursor whenever it changes so that the most recent data is always displayed.
Parameters |
cursor |
Cursor!: The cursor from which to get the data for the groups. |
CursorTreeAdapter
CursorTreeAdapter(
cursor: Cursor!,
context: Context!,
autoRequery: Boolean)
Constructor.
Parameters |
cursor |
Cursor!: The cursor from which to get the data for the groups. |
context |
Context!: The context |
autoRequery |
Boolean: If true the adapter will call Cursor.requery() on the cursor whenever it changes so the most recent data is always displayed. |
Public methods
changeCursor
open fun changeCursor(cursor: Cursor!): Unit
convertToString
open fun convertToString(cursor: Cursor!): String!
getChild
open fun getChild(
groupPosition: Int,
childPosition: Int
): Cursor!
Parameters |
groupPosition |
Int: the position of the group that the child resides in |
childPosition |
Int: the position of the child with respect to other children in the group |
Return |
Cursor! |
the data of the child |
getChildId
open fun getChildId(
groupPosition: Int,
childPosition: Int
): Long
Parameters |
groupPosition |
Int: the position of the group that contains the child |
childPosition |
Int: the position of the child within the group for which the ID is wanted |
Return |
Long |
the ID associated with the child |
getChildView
open fun getChildView(
groupPosition: Int,
childPosition: Int,
isLastChild: Boolean,
convertView: View!,
parent: ViewGroup!
): View!
Parameters |
groupPosition |
Int: the position of the group that contains the child |
childPosition |
Int: the position of the child (for which the View is returned) within the group |
isLastChild |
Boolean: Whether the child is the last child within the group |
convertView |
View!: the old view to reuse, if possible. You should check that this view is non-null and of an appropriate type before using. If it is not possible to convert this view to display the correct data, this method can create a new view. It is not guaranteed that the convertView will have been previously created by getChildView(int,int,boolean,android.view.View,android.view.ViewGroup) . |
parent |
ViewGroup!: the parent that this view will eventually be attached to |
Return |
View! |
the View corresponding to the child at the specified position |
getChildrenCount
open fun getChildrenCount(groupPosition: Int): Int
Parameters |
groupPosition |
Int: the position of the group for which the children count should be returned |
Return |
Int |
the children count in the specified group |
getCursor
open fun getCursor(): Cursor!
getFilter
open fun getFilter(): Filter!
Return |
Filter! |
a filter used to constrain data |
getGroup
open fun getGroup(groupPosition: Int): Cursor!
Parameters |
groupPosition |
Int: the position of the group |
Return |
Cursor! |
the data child for the specified group |
getGroupCount
open fun getGroupCount(): Int
Return |
Int |
the number of groups |
getGroupId
open fun getGroupId(groupPosition: Int): Long
Parameters |
groupPosition |
Int: the position of the group for which the ID is wanted |
Return |
Long |
the ID associated with the group |
getGroupView
open fun getGroupView(
groupPosition: Int,
isExpanded: Boolean,
convertView: View!,
parent: ViewGroup!
): View!
Parameters |
groupPosition |
Int: the position of the group for which the View is returned |
isExpanded |
Boolean: whether the group is expanded or collapsed |
convertView |
View!: the old view to reuse, if possible. You should check that this view is non-null and of an appropriate type before using. If it is not possible to convert this view to display the correct data, this method can create a new view. It is not guaranteed that the convertView will have been previously created by getGroupView(int,boolean,android.view.View,android.view.ViewGroup) . |
parent |
ViewGroup!: the parent that this view will eventually be attached to |
Return |
View! |
the View corresponding to the group at the specified position |
hasStableIds
open fun hasStableIds(): Boolean
Return |
Boolean |
whether or not the same ID always refers to the same object |
isChildSelectable
open fun isChildSelectable(
groupPosition: Int,
childPosition: Int
): Boolean
Parameters |
groupPosition |
Int: the position of the group that contains the child |
childPosition |
Int: the position of the child within the group |
Return |
Boolean |
whether the child is selectable. |
notifyDataSetChanged
open fun notifyDataSetChanged(): Unit
notifyDataSetChanged
open fun notifyDataSetChanged(releaseCursors: Boolean): Unit
Notifies a data set change, but with the option of not releasing any cached cursors.
Parameters |
releaseCursors |
Boolean: Whether to release and deactivate any cached cursors. |
notifyDataSetInvalidated
open fun notifyDataSetInvalidated(): Unit
onGroupCollapsed
open fun onGroupCollapsed(groupPosition: Int): Unit
Parameters |
groupPosition |
Int: The group being collapsed. |
runQueryOnBackgroundThread
open fun runQueryOnBackgroundThread(constraint: CharSequence!): Cursor!
setChildrenCursor
open fun setChildrenCursor(
groupPosition: Int,
childrenCursor: Cursor!
): Unit
Sets the children Cursor for a particular group. If there is an existing cursor it will be closed.
This is useful when asynchronously querying to prevent blocking the UI.
Parameters |
groupPosition |
Int: The group whose children are being set via this Cursor. |
childrenCursor |
Cursor!: The Cursor that contains the children of the group. |
setGroupCursor
open fun setGroupCursor(cursor: Cursor!): Unit
Sets the group Cursor.
Parameters |
cursor |
Cursor!: The Cursor to set for the group. If there is an existing cursor it will be closed. |
Protected methods
bindChildView
protected abstract fun bindChildView(
view: View!,
context: Context!,
cursor: Cursor!,
isLastChild: Boolean
): Unit
Bind an existing view to the child data pointed to by cursor
Parameters |
view |
View!: Existing view, returned earlier by newChildView |
context |
Context!: Interface to application's global information |
cursor |
Cursor!: The cursor from which to get the data. The cursor is already moved to the correct position. |
isLastChild |
Boolean: Whether the child is the last child within its group. |
bindGroupView
protected abstract fun bindGroupView(
view: View!,
context: Context!,
cursor: Cursor!,
isExpanded: Boolean
): Unit
Bind an existing view to the group data pointed to by cursor.
Parameters |
view |
View!: Existing view, returned earlier by newGroupView. |
context |
Context!: Interface to application's global information |
cursor |
Cursor!: The cursor from which to get the data. The cursor is already moved to the correct position. |
isExpanded |
Boolean: Whether the group is expanded. |
getChildrenCursor
protected abstract fun getChildrenCursor(groupCursor: Cursor!): Cursor!
Gets the Cursor for the children at the given group. Subclasses must implement this method to return the children data for a particular group.
If you want to asynchronously query a provider to prevent blocking the UI, it is possible to return null and at a later time call setChildrenCursor(int,android.database.Cursor)
.
It is your responsibility to manage this Cursor through the Activity lifecycle. It is a good idea to use Activity.managedQuery
which will handle this for you. In some situations, the adapter will deactivate the Cursor on its own, but this will not always be the case, so please ensure the Cursor is properly managed.
Parameters |
groupCursor |
Cursor!: The cursor pointing to the group whose children cursor should be returned |
Return |
Cursor! |
The cursor for the children of a particular group, or null. |
newChildView
protected abstract fun newChildView(
context: Context!,
cursor: Cursor!,
isLastChild: Boolean,
parent: ViewGroup!
): View!
Makes a new child view to hold the data pointed to by cursor.
Parameters |
context |
Context!: Interface to application's global information |
cursor |
Cursor!: The cursor from which to get the data. The cursor is already moved to the correct position. |
isLastChild |
Boolean: Whether the child is the last child within its group. |
parent |
ViewGroup!: The parent to which the new view is attached to |
Return |
View! |
the newly created view. |
newGroupView
protected abstract fun newGroupView(
context: Context!,
cursor: Cursor!,
isExpanded: Boolean,
parent: ViewGroup!
): View!
Makes a new group view to hold the group data pointed to by cursor.
Parameters |
context |
Context!: Interface to application's global information |
cursor |
Cursor!: The group cursor from which to get the data. The cursor is already moved to the correct position. |
isExpanded |
Boolean: Whether the group is expanded. |
parent |
ViewGroup!: The parent to which the new view is attached to |
Return |
View! |
The newly created view. |