Detect column where the item is rendered in a RecyclerView
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1
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I have a RecyclerView that uses a GridLayoutManager to render my dataset.
The spanCount for the layout manager is 2, but I am setting a SpanSizeLookup so I can display some items as rows (spanSize=2) and others that only occupy half width (spanSize=1).
layoutManager = new GridLayoutManager(this.getContext(), 2);
layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return getSpanSizeByPosition(position);
}
});
Now I need to detect (in the adapter onBindViewHolder() method if possible) if the item will be rendered on the left or right side, in case it is a "half-width" item.
It would be trivial if all the items were "half-width" items. A simple validation boolean buttonIsOnTheLeft = position % 2 == 0; would be enough. But this doesn't work if not all items are "half-width".
I suspect I will need to work with the layout manager to find that information, but not sure how...
So, is someone seeing how I could achieve this?
android android-recyclerview gridlayoutmanager asked Nov 19 at 16:12
amp
3,83485094
add a comment |
up vote
1
down vote
favorite
I have a RecyclerView that uses a GridLayoutManager to render my dataset.
The spanCount for the layout manager is 2, but I am setting a SpanSizeLookup so I can display some items as rows (spanSize=2) and others that only occupy half width (spanSize=1).
layoutManager = new GridLayoutManager(this.getContext(), 2);
layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return getSpanSizeByPosition(position);
}
});
Now I need to detect (in the adapter onBindViewHolder() method if possible) if the item will be rendered on the left or right side, in case it is a "half-width" item.
It would be trivial if all the items were "half-width" items. A simple validation boolean buttonIsOnTheLeft = position % 2 == 0; would be enough. But this doesn't work if not all items are "half-width".
I suspect I will need to work with the layout manager to find that information, but not sure how...
So, is someone seeing how I could achieve this?
android android-recyclerview gridlayoutmanager asked Nov 19 at 16:12
amp
3,83485094
add a comment |
up vote
1
down vote
favorite
up vote
1
down vote
favorite
I have a RecyclerView that uses a GridLayoutManager to render my dataset.
The spanCount for the layout manager is 2, but I am setting a SpanSizeLookup so I can display some items as rows (spanSize=2) and others that only occupy half width (spanSize=1).
layoutManager = new GridLayoutManager(this.getContext(), 2);
layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return getSpanSizeByPosition(position);
}
});
Now I need to detect (in the adapter onBindViewHolder() method if possible) if the item will be rendered on the left or right side, in case it is a "half-width" item.
It would be trivial if all the items were "half-width" items. A simple validation boolean buttonIsOnTheLeft = position % 2 == 0; would be enough. But this doesn't work if not all items are "half-width".
I suspect I will need to work with the layout manager to find that information, but not sure how...
So, is someone seeing how I could achieve this?
android android-recyclerview gridlayoutmanager asked Nov 19 at 16:12
amp
3,83485094
I have a RecyclerView that uses a GridLayoutManager to render my dataset.
The spanCount for the layout manager is 2, but I am setting a SpanSizeLookup so I can display some items as rows (spanSize=2) and others that only occupy half width (spanSize=1).
layoutManager = new GridLayoutManager(this.getContext(), 2);
layoutManager.setSpanSizeLookup(new GridLayoutManager.SpanSizeLookup() {
@Override
public int getSpanSize(int position) {
return getSpanSizeByPosition(position);
}
});
Now I need to detect (in the adapter onBindViewHolder() method if possible) if the item will be rendered on the left or right side, in case it is a "half-width" item.
It would be trivial if all the items were "half-width" items. A simple validation boolean buttonIsOnTheLeft = position % 2 == 0; would be enough. But this doesn't work if not all items are "half-width".
I suspect I will need to work with the layout manager to find that information, but not sure how...
So, is someone seeing how I could achieve this?
android android-recyclerview gridlayoutmanager android android-recyclerview gridlayoutmanager asked Nov 19 at 16:12
amp
3,83485094
asked Nov 19 at 16:12
amp
3,83485094
asked Nov 19 at 16:12
amp
3,83485094
asked Nov 19 at 16:12
amp
3,83485094
asked Nov 19 at 16:12
amp
3,83485094
3,83485094
add a comment |
add a comment |
2 Answers
2
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oldest
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up vote
1
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You can read GridLayoutManager.LayoutParams of each ViewHolder, then You will get access to getSpanIndex and getSpanSize.
However those values are set after view is laid out which happens later (and more often) than onBindViewHolder(). Callback for this event is onViewAttachedToWindow(RecyclerView.ViewHolder holder) method:
class Adapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
// ...
@Override
public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
if(holder.itemView.getLayoutParams() instanceof GridLayoutManager.LayoutParams){
GridLayoutManager.LayoutParams lp = (GridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
holder.title.setText("In column "+lp.getSpanIndex()+", size "+lp.getSpanSize());
}
}
}
answered Nov 19 at 16:50
Pawel
2,7221211
Thanks for your help. I didn't know about that onViewAttachedToWindowd(). However, I would need to notify the adapter that the item changed, so the information is updated right? It is no possible in theonBindViewHolder()method? Or somewhere before the view is rendered?
– amp
Nov 19 at 17:44
add a comment |
up vote
0
down vote
accepted
I found the solution. In the onBindViewHolder() method I just need to call this method that I implemented:
private boolean isButtonIsOnTheLeft(int position, NodeStructureTreeViewAdapter adapter) {
GridLayoutManager layoutManager = adapter.getLayoutManager();
int spanIndex = layoutManager.getSpanSizeLookup().getSpanIndex(position, layoutManager.getSpanCount());
return spanIndex == 0;
}
Of course, I implemented the method getLayoutManager() in my adapter the retrieves it from the instance of the recyclerView.
answered Nov 20 at 9:26
amp
3,83485094
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
1
down vote
You can read GridLayoutManager.LayoutParams of each ViewHolder, then You will get access to getSpanIndex and getSpanSize.
However those values are set after view is laid out which happens later (and more often) than onBindViewHolder(). Callback for this event is onViewAttachedToWindow(RecyclerView.ViewHolder holder) method:
class Adapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
// ...
@Override
public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
if(holder.itemView.getLayoutParams() instanceof GridLayoutManager.LayoutParams){
GridLayoutManager.LayoutParams lp = (GridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
holder.title.setText("In column "+lp.getSpanIndex()+", size "+lp.getSpanSize());
}
}
}
answered Nov 19 at 16:50
Pawel
2,7221211
Thanks for your help. I didn't know about that onViewAttachedToWindowd(). However, I would need to notify the adapter that the item changed, so the information is updated right? It is no possible in theonBindViewHolder()method? Or somewhere before the view is rendered?
– amp
Nov 19 at 17:44
add a comment |
up vote
1
down vote
You can read GridLayoutManager.LayoutParams of each ViewHolder, then You will get access to getSpanIndex and getSpanSize.
However those values are set after view is laid out which happens later (and more often) than onBindViewHolder(). Callback for this event is onViewAttachedToWindow(RecyclerView.ViewHolder holder) method:
class Adapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
// ...
@Override
public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
if(holder.itemView.getLayoutParams() instanceof GridLayoutManager.LayoutParams){
GridLayoutManager.LayoutParams lp = (GridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
holder.title.setText("In column "+lp.getSpanIndex()+", size "+lp.getSpanSize());
}
}
}
answered Nov 19 at 16:50
Pawel
2,7221211
Thanks for your help. I didn't know about that onViewAttachedToWindowd(). However, I would need to notify the adapter that the item changed, so the information is updated right? It is no possible in theonBindViewHolder()method? Or somewhere before the view is rendered?
– amp
Nov 19 at 17:44
add a comment |
up vote
1
down vote
up vote
1
down vote
You can read GridLayoutManager.LayoutParams of each ViewHolder, then You will get access to getSpanIndex and getSpanSize.
However those values are set after view is laid out which happens later (and more often) than onBindViewHolder(). Callback for this event is onViewAttachedToWindow(RecyclerView.ViewHolder holder) method:
class Adapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
// ...
@Override
public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
if(holder.itemView.getLayoutParams() instanceof GridLayoutManager.LayoutParams){
GridLayoutManager.LayoutParams lp = (GridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
holder.title.setText("In column "+lp.getSpanIndex()+", size "+lp.getSpanSize());
}
}
}
answered Nov 19 at 16:50
Pawel
2,7221211
You can read GridLayoutManager.LayoutParams of each ViewHolder, then You will get access to getSpanIndex and getSpanSize.
However those values are set after view is laid out which happens later (and more often) than onBindViewHolder(). Callback for this event is onViewAttachedToWindow(RecyclerView.ViewHolder holder) method:
class Adapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{
// ...
@Override
public void onViewAttachedToWindow(@NonNull RecyclerView.ViewHolder holder) {
if(holder.itemView.getLayoutParams() instanceof GridLayoutManager.LayoutParams){
GridLayoutManager.LayoutParams lp = (GridLayoutManager.LayoutParams) holder.itemView.getLayoutParams();
holder.title.setText("In column "+lp.getSpanIndex()+", size "+lp.getSpanSize());
}
}
}
answered Nov 19 at 16:50
Pawel
2,7221211
answered Nov 19 at 16:50
Pawel
2,7221211
answered Nov 19 at 16:50
Pawel
2,7221211
answered Nov 19 at 16:50
Pawel
2,7221211
2,7221211
Thanks for your help. I didn't know about that onViewAttachedToWindowd(). However, I would need to notify the adapter that the item changed, so the information is updated right? It is no possible in theonBindViewHolder()method? Or somewhere before the view is rendered?
– amp
Nov 19 at 17:44
add a comment |
Thanks for your help. I didn't know about that onViewAttachedToWindowd(). However, I would need to notify the adapter that the item changed, so the information is updated right? It is no possible in theonBindViewHolder()method? Or somewhere before the view is rendered?
– amp
Nov 19 at 17:44
Thanks for your help. I didn't know about that onViewAttachedToWindowd(). However, I would need to notify the adapter that the item changed, so the information is updated right? It is no possible in the
onBindViewHolder() method? Or somewhere before the view is rendered?– amp
Nov 19 at 17:44
Thanks for your help. I didn't know about that onViewAttachedToWindowd(). However, I would need to notify the adapter that the item changed, so the information is updated right? It is no possible in the
onBindViewHolder() method? Or somewhere before the view is rendered?– amp
Nov 19 at 17:44
add a comment |
up vote
0
down vote
accepted
I found the solution. In the onBindViewHolder() method I just need to call this method that I implemented:
private boolean isButtonIsOnTheLeft(int position, NodeStructureTreeViewAdapter adapter) {
GridLayoutManager layoutManager = adapter.getLayoutManager();
int spanIndex = layoutManager.getSpanSizeLookup().getSpanIndex(position, layoutManager.getSpanCount());
return spanIndex == 0;
}
Of course, I implemented the method getLayoutManager() in my adapter the retrieves it from the instance of the recyclerView.
answered Nov 20 at 9:26
amp
3,83485094
add a comment |
up vote
0
down vote
accepted
I found the solution. In the onBindViewHolder() method I just need to call this method that I implemented:
private boolean isButtonIsOnTheLeft(int position, NodeStructureTreeViewAdapter adapter) {
GridLayoutManager layoutManager = adapter.getLayoutManager();
int spanIndex = layoutManager.getSpanSizeLookup().getSpanIndex(position, layoutManager.getSpanCount());
return spanIndex == 0;
}
Of course, I implemented the method getLayoutManager() in my adapter the retrieves it from the instance of the recyclerView.
answered Nov 20 at 9:26
amp
3,83485094
add a comment |
up vote
0
down vote
accepted
up vote
0
down vote
accepted
I found the solution. In the onBindViewHolder() method I just need to call this method that I implemented:
private boolean isButtonIsOnTheLeft(int position, NodeStructureTreeViewAdapter adapter) {
GridLayoutManager layoutManager = adapter.getLayoutManager();
int spanIndex = layoutManager.getSpanSizeLookup().getSpanIndex(position, layoutManager.getSpanCount());
return spanIndex == 0;
}
Of course, I implemented the method getLayoutManager() in my adapter the retrieves it from the instance of the recyclerView.
answered Nov 20 at 9:26
amp
3,83485094
I found the solution. In the onBindViewHolder() method I just need to call this method that I implemented:
private boolean isButtonIsOnTheLeft(int position, NodeStructureTreeViewAdapter adapter) {
GridLayoutManager layoutManager = adapter.getLayoutManager();
int spanIndex = layoutManager.getSpanSizeLookup().getSpanIndex(position, layoutManager.getSpanCount());
return spanIndex == 0;
}
Of course, I implemented the method getLayoutManager() in my adapter the retrieves it from the instance of the recyclerView.
answered Nov 20 at 9:26
amp
3,83485094
edited Nov 20 at 9:39
answered Nov 20 at 9:26
amp
3,83485094
answered Nov 20 at 9:26
amp
3,83485094
answered Nov 20 at 9:26
amp
3,83485094
3,83485094
add a comment |
add a comment |
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