I'm stuck on a little problem.
When I click on a row in my RecyclerView, I'd like to change its color to some other color (i.e.: red).
Then, if I click this row again, I would like to set its color back to the normal one (i.e.: white).
Then, if I click on a second row or n-th row, I would like to do the same.
I've tried to work on the RecyclerView Adapter class, in my ViewHolder I tried some ideas counting user clicks, setting a boolean to check the colored rows, and getAdapterPosition to know what is the row's position... but actually all my tries failed!
Would you please help me with that problem?
It seems that I'm close to the solution, but need a little help
You're going to need to keep track of which items were selected on the list (otherwise any changes to the view will simply be recycled).
Keep a list of selected items within your adapter. In the adapter's onBindViewHolder you can check against the list and if the list contains the view/item, you can color the view accordingly.
Edit: Refer here for a working example
How to properly highlight selected item on RecyclerView?
Related
I have a listview and a corresponding listview adapter.
The views displayed in the Listview have I written myself and it's a framelayout with one button and one imagebutton. The imagebutton is a red cross that deletes the entry and the regular button selects the entry.
When the user presses the regular button, that item is selected and I want to show this to the user by setting the background of that item to green. The application stores which item the user selected and the next time the listview is rendered, THAT item should be selected and green.
Notice that there should be one and EXACTLY one selected item in my listview at all times.
In the getView(.. method in my adaper, it's very easy to change color of the button when the user clicks it. But the button that was green before the user clicked is impossible for me to reference.
I tried storing a reference the previously selected button, but it never repainted
I tried removing and adding the data item from the list to trigger notifyDataSetChanged but it never repainted
I tried setChoiceMode(ListView.CHOICE_MODE_SINGLE), but that led nowhere because I don't know how to catch the choice in my getView method and paint differently depending on wheter it's selected or not.
All guides I see suggest using notifyDataSetChanged. However, the underlying data is NOT changed in this case and it is not correct (or possible) solution.
So I think that my problem boils down to: HOW can I reference another view in my listview??
(And Yes, I have seen this post: Highlight selected item in ListView on Android . It describes my problem and is answered with "and then change the color of previous selected item's background back to normal" but I still can't refer to the PREVIOUS selected item.
Thanks!
Why don't you use Radio Buttons ? This is exactly the design you need. You can add a "red cross" on each line to delete the line. The selected line is unique and you can iterate on RadioButton.isChecked(); of your RadioGroup to set the background color accordingly.
In my layout I have a button and a listview. How can I change the imageview of item I selected when the button is clicked. So lets say, I select 5 items, and after I click the button, images for those 5 items will be changed.
So I am confused what function I should use. Right now i used button.setOnClickListener but it seems wrong because only the very first item's imageview will be changed when button clicked. Should I use listview.setItemOnClickListener? Or is there any other way I can do this?
Thanks a lot!
Add a boolean to the data object in your adapter. Say you've got ArrayAdapter<MyDataObject>. Add some kind of "selected" field in the MyDataObject, and toggle it when you "select" the row.
Override getView in the adapter (you'll need a custom Adapter, btw. I'd just extend ArrayAdapter). When you render the row, if the "selected" field is true, show the "other" image.
When you click the button, call 'notifyDataSetChanged' on the adapter. The will cause the visible rows to refresh themselves (and call getView for each).
I think that'll work.
Since you only want images to change when you click the button, you'll need to have some kind of global boolean, so the getView won't show the image until the button has been clicked.
The complication here is, you have to deal with rows that may have been scrolled out of view, which don't have active views, but logically exist. It would be really hard to explain the concept here. I'd suggest some tutorials on ListView if you're not familiar with the recycling of row views.
You can used custom baseadapter for listview and setonclicklistener in the getView() method.... see tutorial here this is hope for help
You can use button click listener as well as on itemClickListener too but to make a image view in selected state in a list, you have to call setSelected method of imageview parent layout.
Please put a comment if you don't get me.
Thanks
I am using a ListView in combination with a HashList to show data from an SQL Database through JSON. Everything works fine. But now I want to have a special feature.
In the ListView are round about 400 Items. So if i click one of the item to view its content and switch via Backbutton back to the Listview, i want to have the viewed Item from the Listview being marked in another color so that the user sees directly which oh the items he already has clicked.
I painted an little grafik for you, for better understanding
On the left side, the original View. After i View the 1st,5th and 8th Item of the list, the list should look like at the right side.
Is this possible?
You can implement your own adapter, then have an boolean array to store the current status of every row, and in the getView function assign a different color to the background of the selected rows based on your boolean array.
For this you will need also to set an onClick event in your rows to open the previsualization view and there also check the boolean array as "visited".
For more info about how to make custom efficient adapters, please read this
To simply let the user choice more than one row you can use
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
in your list
I want my ListView to work something like the following:
When I press a button (probably from context-menu), I want the user to be able to select more then one item from ListView (probably using check-boxes), but those check-boxes should not be visible before that.
So, the point is, after the user presses a button (let's say "Delete more items"), the listview, should update itself, and appear on every row of the list, a checkbox should appear (allowing me to select the items ID to pass those to server).
How can I achieve that, without having to recreate the list from zero? (how to setVisibility ON, keeping the other content of the ListView as it is, and not doing another request to server).
PS. If you guys, have another better idea, on achieving the Delete More Items, would be much appreciated!
This is just an idea, haven't tried it myself: you build in a checkbox in your listitem layout. Normally, in the getView of your adapter, you set it invisible with
checkBox.setVisibility(8);
When you want to show them, you set some boolean
showBoxes
of your adapter to true, then in the getView oyu don't hide the checkboxes.
Then
notifyDataSetChanged
on the adapter.
Hope it's clear what I mean.
In Android, I want to present the user with a list. When an item on the list is selected some action is performed, and this list item is no longer selectable. It is also 'grayed out' or the like to indicate that it cannot be selected the next time the list is displayed. I have seen the isSelectable() override in Adapter, but I believe this causes the item to be treated as a separator, which causes visual problems. And I have not found a way to 'gray out' an item. Any ideas? Thanks...
As far as graying out an item. I'm not sure if this is the best way, but it's what I do:
view.setAlpha(75);
view.setBackgroundColor(Color.GRAY);
I'm basically making the item transparent and then setting the background color to gray. If you're reusing your list items you should also change them back to their original state if the condition is not met, i.e.:
view.setAlpha(255);
view.setBackgroundColor(Color.WHITE);
that is, if your original state was no transparency and the background color was white.
You need the view to be disabled. If you are creating the views just call .setDisabled(boolean) on the top view. Setting the list item to be disabled doesn't work very well in my experience.
Here is the solution I am using. I set up an OnItemClickListener for my ListView. When an item in the list is clicked, I take the passed in View and call setEnabled(false) on it. This will gray out the item. However, subsequent clicks on this item will still call the onItemClick method. So, you will need to check on each click if the item is enabled/disabled and act accordingly.