**! ! Warning**: Do not merge before testing every API call and database
read involving JSON !
**Gson** is obsolete and has been superseded by **Moshi**. But more
importantly, parsing Kotlin objects using Gson is _dangerous_ because
Gson uses Java serialization and is **not Kotlin-aware**. This has two
main consequences:
- Fields of non-null types may end up null at runtime. Parsing will
succeed, but the code may crash later with a `NullPointerException` when
trying to access a field member;
- Default values of constructor parameters are always ignored. When
absent, reference types will be null, booleans will be false and
integers will be zero.
On the other hand, Kotlin-aware parsers like **Moshi** or **Kotlin
Serialization** will validate at parsing time that all received fields
comply with the Kotlin contract and avoid errors at runtime, making apps
more stable and schema mismatches easier to detect (as long as logs are
accessible):
- Receiving a null value for a non-null type will generate a parsing
error;
- Optional types are declared explicitly by adding a default value. **A
missing value with no default value declaration will generate a parsing
error.**
Migrating the entity declarations from Gson to Moshi will make the code
more robust but is not an easy task because of the semantic differences.
With Gson, both nullable and optional fields are represented with a null
value. After converting to Moshi, some nullable entities can become
non-null with a default value (if they are optional and not nullable),
others can stay nullable with no default value (if they are mandatory
and nullable), and others can become **nullable with a default value of
null** (if they are optional _or_ nullable _or_ both). That third option
is the safest bet when it's not clear if a field is optional or not,
except for lists which can usually be declared as non-null with a
default value of an empty list (I have yet to see a nullable array type
in the Mastodon API).
Fields that are currently declared as non-null present another
challenge. In theory, they should remain as-is and everything will work
fine. In practice, **because Gson is not aware of nullable types at
all**, it's possible that some non-null fields currently hold a null
value in some cases but the app does not report any error because the
field is not accessed by Kotlin code in that scenario. After migrating
to Moshi however, parsing such a field will now fail early if a null
value or no value is received.
These fields will have to be identified by heavily testing the app and
looking for parsing errors (`JsonDataException`) and/or by going through
the Mastodon documentation. A default value needs to be added for
missing optional fields, and their type could optionally be changed to
nullable, depending on the case.
Gson is also currently used to serialize and deserialize objects to and
from the local database, which is also challenging because backwards
compatibility needs to be preserved. Fortunately, by default Gson omits
writing null fields, so a field of type `List<T>?` could be replaced
with a field of type `List<T>` with a default value of `emptyList()` and
reading back the old data should still work. However, nullable lists
that are written directly (not as a field of another object) will still
be serialized to JSON as `"null"` so the deserializing code must still
be handling null properly.
Finally, changing the database schema is out of scope for this pull
request, so database entities that also happen to be serialized with
Gson will keep their original types even if they could be made non-null
as an improvement.
In the end this is all for the best, because the app will be more
reliable and errors will be easier to detect by showing up earlier with
a clear error message. Not to mention the performance benefits of using
Moshi compared to Gson.
- Replace Gson reflection with Moshi Kotlin codegen to generate all
parsers at compile time.
- Replace custom `Rfc3339DateJsonAdapter` with the one provided by
moshi-adapters.
- Replace custom `JsonDeserializer` classes for Enum types with
`EnumJsonAdapter.create(T).withUnknownFallback()` from moshi-adapters to
support fallback values.
- Replace `GuardedBooleanAdapter` with the more generic `GuardedAdapter`
which works with any type. Any nullable field may now be annotated with
`@Guarded`.
- Remove Proguard rules related to Json entities. Each Json entity needs
to be annotated with `@JsonClass` with no exception, and adding this
annotation will ensure that R8/Proguard will handle the entities
properly.
- Replace some nullable Boolean fields with non-null Boolean fields with
a default value where possible.
- Replace some nullable list fields with non-null list fields with a
default value of `emptyList()` where possible.
- Update `TimelineDao` to perform all Json conversions internally using
`Converters` so no Gson or Moshi instance has to be passed to its
methods.
- ~~Create a custom `DraftAttachmentJsonAdapter` to serialize and
deserialize `DraftAttachment` which is a special entity that supports
more than one json name per field. A custom adapter is necessary because
there is not direct equivalent of `@SerializedName(alternate = [...])`
in Moshi.~~ Remove alternate names for some `DraftAttachment` fields
which were used as a workaround to deserialize local data in 2-years old
builds of Tusky.
- Update tests to make them work with Moshi.
- Simplify a few `equals()` implementations.
- Change a few functions to `val`s
- Turn `NetworkModule` into an `object` (since it contains no abstract
methods).
Please test the app thoroughly before merging. There may be some fields
currently declared as mandatory that are actually optional.
There are some new rules, I think they mostly make sense, except for the
max line length which I had to disable because we are over it in a lot
of places.
---------
Co-authored-by: Goooler <wangzongler@gmail.com>
The idea here is: Everytime we get hold of a new version of a post, we
update everything about that post everywhere.
This makes the distincion between different event types unnecessary, as
everythng is just a `StatusChangedEvent`.
The main benefit is that posts should be up-to-date more often, which is
important considering there is now editing and #3413
Update to Kotlin 1.9.0 and migrate to newer language idioms.
- Remove unnecessary @OptIn for features migrated to mainstream
- Use `data object` where appropriate
- Use new enum `entries` property
* Replace "warn"-filtered posts in timelines and thread view with placeholders
* Adapt hashtag muting interface
* Rework filter UI
* Add icon for account preferences
* Clean up UI
* WIP: Use chips instead of a list. Adjust padding
* Scroll the filter edit activity
Nested scrolling views (e.g., an activity that scrolls with an embedded list
that also scrolls) can be difficult UI.
Since the list of contexts is fixed, replace it with a fixed collection of
switches, so there's no need to scroll the list.
Since the list of actions is only two (warn, hide), and are mutually
exclusive, replace the spinner with two radio buttons.
Use the accent colour and title styles on the different heading titles in
the layout, to match the presentation in Preferences.
Add an explicit "Cancel" button.
The layout is a straightforward LinearLayout, so use that instead of
ConstraintLayout, and remove some unncessary IDs.
Update EditFilterActivity to handle the new layout.
* Cleanup
* Add more information to the filter list view
* First pass on code review comments
* Add view model to filters activity
* Add view model to edit filters activity
* Only use the status wrapper for filtered statuses
* Relint
---------
Co-authored-by: Nik Clayton <nik@ngo.org.uk>
* Improve the actual and perceived speed of thread loading
To improve the actual speed, note that if the user has opened a thread from
their home timeline then the initial status is cached in the database. Other
statuses in the same thread may be cached as well.
So try and load the initial status from the database, falling back to the
network if it's not present (e.g., the user has opened a thread from the
local or federated timelines, or a search).
Introduce a new loading state to deal with this case.
In typical cases this allows the UI to display the initial status immediately
with no need to show a progress indicator.
To improve the perceived speed, delay showing the initial loading circular
progress indicators by 500ms. If loading the initial status completes within
that time no spinner is shown and the user will perceive the action as
close-to-immediate
(https://www.nngroup.com/articles/response-times-3-important-limits/).
Additionally, introduce an extra indeterminate progress indicator.
The new indicator is linear, anchored to the bottom of the screen, and shows
progress loading ancestor/descendant statuses. Like the other indicator is
also delayed 500ms from when ancestor/descendant status information is
fetched, and if the fetch completes in that time it will not be shown.
* Mark `getStatus` as suspend so it doesn't run on the main thread
* Save an allocation, use an isDetailed parameter to TimelineStatusWithAccount.toViewData
Rename Status.toViewData's "detailed" parameter to "isDetailed" for
consistency with other uses.
* Ensure suspend functions run to completion when testing
* Delay-load the status from the network even if it's cached
This speeds up the UI while ensuring it will eventually contain accurate data
from the remote.
* Load the network status before updating the list
Avoids excess animations if the network copy has changes
* Fix UI flicker when loading reblogged statuses
* Lint
* Fixup tests
* show status edits part 1
* show status edits part 2 - load status edits
* fix code formatting
* add dialog to show status edits
* small improvements
* use ALIGN_CENTER to position status visibility icon when possible
* rename status_timestamp_info view to status_meta_info
* make dateFormat static
* remove commented-out code
* move edits to dedicated fragment
* initial class setup
* handle events and filters
* handle status state changes
* code formatting
* fix status filtering
* cleanup code a bit
* implement removeAllByAccountId
* move toolbar into fragment, implement menu
* error and load state handling
* fix pull to refresh
* implement reveal button
* use requireContext() instead of context!!
* jump to detailed status
* add ViewThreadViewModelTest
* fix ktlint
* small code improvements (thx charlag)
* add testcase for toggleRevealButton
* add more state change testcases to ViewThreadViewModel
Christophe Beyls
Zongle Wang
Willow
Konrad Pozniak
Levi Bard
Nik Clayton