ListView in Android supports header and footer views -- views
that do not belong to the underlying adapter but otherwise
show up in the list and scroll along with the contents.
However, they only work if you have not yet set your own
adapter and are therefore not terribly flexible.
The SackOfViewsAdapter is another way of approaching this.
Here, you provide the Views that make up the rows, and the
adapter feeds them to Android as if they were newly created.
The SackOfViewsAdapter is designed to be subclassed, mostly
to determine how isEnabled() behaves, so you can control
which of those views are selectable and which simply scroll
with the list.
While standalone, this is not terribly useful, in conjunction with other adapters, perhaps other ones in the CWAC collection, it has greater benefit.
This Android library project is
available as a JAR
or as an artifact for use with Gradle. To use that, add the following
blocks to your build.gradle file:
repositories {
maven {
url "https://repo.commonsware.com.s3.amazonaws.com"
}
}
dependencies {
compile 'com.commonsware.cwac:sacklist:1.0.0'
}Or, if you cannot use SSL, use http://repo.commonsware.com for the repository
URL.
NOTE: The JAR name, as of v1.0.1, has a cwac- prefix, to help distinguish it from other JARs.
You can use SackOfViewsAdapter directly or subclass it. The
latter is needed to support on-demand row creation or controlling
which rows are/are not enabled.
SackOfViewsAdapter either takes a count or a List of View objects
as parameters. In the first case, the count indicates how many
total rows there will be. If you choose to pass in a List,
and you want to add to it later on, make sure it is a mutable
list (e.g., created by new ArrayList<View>()).
If you pass in just a count of rows in the constructor, you
need to extend SackOfViewsAdapter and override newView(),
to return a row View given a position and the ViewGroup that
is the row's parent (e.g., a ListView). SackOfViewsAdapter
will then hang onto that row and return it to Android whenever
that position is requested.
If you pass in a List of View objects in the constructor,
some of those positions in the list can be null. In that case,
you again have to extend SackOfViewsAdapter and override
newView(), but you will only be called for those rows
initially defined as null.
You are welcome to override other methods as well, since this
is just an Adapter. In particular, if all rows are not
enabled for selection, you will want to override isEnabled()
and return true or false as needed to indicate which rows are
selectable and which are not (e.g., header rows).
You can call hasView() on a SackOfViewsAdapter to determine
if it contains a certain View or not.
None at present.
This project should work on API Level 4 and higher, except for any portions that may be noted otherwise in this document. Please report bugs if you find features that do not work on API Level 4 and are not noted as requiring a higher version.
This is version v1.0.1 of this module.
In the demo/ sub-project you will find
a sample activity that demonstrates the use of SackOfViewsAdapter.
The code in this project is licensed under the Apache Software License 2.0, per the terms of the included LICENSE file.
If you have questions regarding the use of this code, please post a question
on StackOverflow tagged with
commonsware-cwac and android after searching to see if there already is an answer. Be sure to indicate
what CWAC module you are having issues with, and be sure to include source code
and stack traces if you are encountering crashes.
If you have encountered what is clearly a bug, please post an issue. Be certain to include complete steps for reproducing the issue.
Do not ask for help via Twitter.
- v1.0.1: updated Gradle files and manifest for compatibility, added
cwac-prefix to JAR - v1.0.0: migrated to Gradle and published AAR
- v0.4.0: added
hasView() - v0.3.1: fixed copy-and-paste error in build.xml
- v0.3.0: converted to Android library project
