I have been trying to but can't figure quite how to create a gridview displaying items from a online strore and to be able to compare between two items that have been selected from a checkbox. Does anyone how to do this?
You could overwrite the equality operator and hashcode for your GridView Item class.
Official Equality override documentation.
Then you can just compare those items via a typical == operator. Remember, always override hashCode property when overriding the == operator.
There's also a common library that is used to simplify this called Equatable. The usage is pretty straight forward if you check the examples on pub.dev
I don't have access to the items from your online store, instead I used freely available data about Harry Potter Characters.
I used a gridview to display the data items. Once two items are selected a bottomsheet pops up showing the comparison.
Here is a gif of the working app, code can be found here.
I used flutter_bloc to implement the bloc pattern to this app. All the logic is managed in CharacterBloc which responds to three events
Fetching data
Selecting characters
De-selecting characters
Related
I would like to know your idea about the best method to present several personalized horizontal lists, in the spotfy style.
With different preferences and musical styles.
The best way would be to create several listviews? or structure a database and make it somehow present only a few things on the user's homepage?
any suggestion?
i dont think there would be any problem displaying different list view on home showing few items ( 3 or 4 ) of that list and a button above each listView as View All on tapping using that list all items on that category personal screen
you can add multiple ListView as you can possible Try SingleChildScrollView for multiple ListView or Layouts
Refer Official Docs : docs
I am new to IOS development. I am trying to add simple TextField for entering Occupation. I would like to show the user some matching suggestions as they user type (from a set of occupations that I already have). This is a very common usecase. Is there a idiomatic ways of doing this? In Android there is an AutoCompleteTextView in the standard view library which takes in an array of suggestions during initalization. I could not find anything similar in IOS.
You can use some 3rd party libraries available for Auto complete text field
but
the best and easy approach from my perspective is to use UITextField and at bottom add UITableview. So the concept is when you type any character in textfield you need to filter some data from tableview and reload tableview
Check the below link you can get the suitable answer from here...
Getting autocomplete to work in swift
I need a flutter list package with the following features:
Only renders items in/near visible range (virtualized)
Supports different item heights.
Reorderable through drag and drop
When an item is dragged to the edge of the screen, the list scrolls
When items enter or exit, the list animates nicely
The package ReorderableListView.builder (https://api.flutter.dev/flutter/material/ReorderableListView/ReorderableListView.builder.html) supports 1,3 and 4. No support for 5. Reordering animation was bad for items with differing heights (2) when I tried it out.
The package implicitly_animated_reorderable_list
(https://pub.dev/packages/implicitly_animated_reorderable_list/changelog) supports 3 and 5. Nothing mentioned about 1 or 2 in its readme, and a comment from January here (Flutter: Reorderable AND Animated ListView - any idea?) suggests 4 is missing.
Looking for advice on how to achieve this:
An amazing package that can do all 5.
A way to add features of these different packages together somehow. Is that at all possible?
Advice on forking or not forking and just starting from scratch.
In regards to forking what in your opinion is the most/least trivial of these features to build from scratch?
I'm new to Flutter, so anything I don't know enough to ask about in relation to this subject is also greatly appreciated.
Own answer:
There really isn't a need for any plugins or forks. ReorderableListview.builder can be used to accomplish all 5.
Not sure how I botched the code that made me think ReorderableListView.builder wasn't handling different heights of items correctly, but whatever the glitch was (maybe related to keys?), I'm not able to reproduce it. Interesting that all the docs/tutorials I found only show statically sized list items when dynamically sized list items are no problem.
As for the animated exits and entrances (i.e. not letting the list items seem to jump up and down in a disorienting way), this is really trivial to do by animating height with AnimatedContainer. The existence of a separate AnimatedList widget and ImplicitlyAnimatedList plugin threw me off a bit.
I have been learning about Bloc Pattern in Flutter for weeks, but it seems it's a bit difficult when I implement in my real project.
For example:
I created a bloc (product_bloc) for loading all products from my server to a Listview. And on the same screen I have a Category Combobox for filter the product in my Listview by category. At this point, I want to load all my categories from server to the Combobox too. Should I create a new bloc (category_bloc) for loading category to Combobox at this point? It means that the state for product and state for category should be different in this case right? What should I do then? For one screen, we can use only one bloc right? Thanks in advance for you help :)
In your example, I think that the category it's only a atribute of the product. You don't apear of been manipulating categories but only selecting one to filter your results. In my opinion, you can use it in the same block.
But it's not a problem to use more than one blocs per pages/screens. I use an Authentication and an 'Entity' bloc in all of my Apps that I builded until today.
As shown in the documentation example you can implement a selectable List.
I was wondering how would one be able to make the list to support multiple selections.
The method that was used in the example is makeSelectable. There doesn't seem to be any documentation regarding that method and I wasn't able to find anything substantial in the issues of their git project.
Any help will be appreciated.
Create a state variable selectedItems to keep track of selected items of the list.
ListItem supports checkboxes, so you can create a checkbox for each ListItem, add an onCheck handler to it and pass to it a unique value to identify which checkbox is checked and based on that you can modify the state variable selectedItems.
Alternatively, you can use Menu in place of List as it has the property multiple. You can set it to true and that's it.