I've been trying to write some dynamically generated layout code for a simple app I came up with. I want to display a vertical row of cards, each on containing an undefined number of vertically aligned text boxes.
I wrote the code to generate these and populate the text, but it doesn't appear to be working and I can't figure it out for the life of me.
I'm new to Android Studio, and Java is still relatively fresh to me as well, so I could well be missing something quite obvious here.
I've tried using a few different types of View in A. Studio, and so far most work by themselves, but none can be contained within a card which would be ideal for me. Dynamically creating and editing properties of textViews works fine, but once I include the card view they no longer appear using the exact same code.
//Define Params
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
params.setMargins(left,top,right,bottom);
//Add a card for each ingredient
for (Ingredient ing : ingredients)
{
CardView card = new CardView(this);
CardView.LayoutParams cardParams = new CardView.LayoutParams(CardView.LayoutParams.WRAP_CONTENT, 200);
card.setLayoutParams(cardParams);
card.setRadius(15);
card.setPadding(25,25,25,25);
card.setElevation(10);
card.setMaxCardElevation(30);
card.setBackgroundColor(Color.DKGRAY);
//Make a grid for each card, text on the left, image on the right
LinearLayout linearLayoutInCard = new LinearLayout(card.getContext());
LinearLayout.LayoutParams layoutParamsInCard = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.MATCH_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT);
linearLayoutInCard.setLayoutParams(layoutParamsInCard);
card.addView(linearLayoutInCard);
for(int x = 0; x < 3; x++)
{
TextView textView = new TextView(this);
textView.setLayoutParams(params);
textView.setPadding(left, top, right, bottom);
textView.setTextSize(15);
textView.setElevation(11);
textView.setTextColor(Color.WHITE);
linearLayoutInCard.addView(textView);
switch (x)
{
case 0:
textView.setText(ing.name);
break;
case 1:
textView.setText(ing.price);
break;
case 2:
//textView.setText(ing.calories);
break;
}
}
I'm expecting a vertical row of cards with text boxes vertically aligned withing them, each with their own content (this whole script will only make one card for now, but that's a data driven thing) yet when I run the application, I get nothing but a blank screen.
Before venturing much further...this could be an example of the XY Problem.
Maybe have a look at the RecyclerView option?
RecyclerViews are entirely designed to manage the UI look and responsiveness of changing/scrolling data sets.
They can be a bit "what the heck" at first...but once writing them a few times, your UI look and code base is a lot more efficient and clean.
RecyclerView example Youtube
Related
My Problem: I want to create a for loop in the onCreate() method to save imageViews dynamically. I am being able to do everything properly it's just that the imageView is displayed at the top left most corner, i.e i am not being able to assign it it's alignment.
My Code:
RelativeLayout layout = findViewById(R.id.relativeLayout);
for(int i=0;i<3;i++)
{
ImageView image = new ImageView(this);
image.setMaxHeight(200);
image.setMaxWidth(200);
//CODE TO ADD THE ALIGNMENT OF THE IMAGE
image.setImageResource(R.drawable.red);
layout.addView(image);
}
Try this one:
for(int i=0;i<3;i++)
{
ImageView image = new ImageView(this);
image.setMaxHeight(200);
image.setMaxWidth(200);
//CODE TO ADD THE ALIGNMENT OF THE IMAGE
image.setImageResource(R.drawable.red);
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.MarginLayoutParams.MATCH_PARENT, 200);
layoutParams.setMargins(40, 40, 40, 40);
image.setLayoutParams(layoutParams);
layout.addView(image);
}
The legal values can be found at https://developer.android.com/reference/android/view/View.html#setTextAlignment(int)
But this has no effect on an ImageView. I'm not sure what you're actually truing to do, so I can't help you. My best guess is you're trying to arrange views within the parent layout somehow, but to help with that we'd need to know the type of layout the parent is and what you want to do.
So I'm trying to add a RelativeLayout to a RelativeLayout however, when I run my app, it's an IllegalStateException that shows this error: The specified child already has a parent. You must call removeView() on the child's parent first. I'm sure you guys have seen this before. My question is how do I properly nest two relative layouts together?
Here is the code snippet that produces the exception:
RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.MATCH_PARENT);
RelativeLayout newFrame = new RelativeLayout(vidRipperService.getBaseContext());
newFrame.setLayoutParams(layoutParams);
// configure image view constraints...
// have the frame be right in the center of the layout.
ImageView editedFrame = new ImageView(vidRipperService.getBaseContext());
// Note: when doing padding the height and the width must be a multiple of two. A nice example is 70+30 = 100/2 = 50, but 80+30 = 110/2 = 55 <- not a multiple of two. Keep this in mind.
editedFrame.setId(View.generateViewId());
editedFrame.setPadding(30,30,30,0); // padding of 30 around the whole view.
editedFrame.setImageBitmap(frame); // set the frame to be that of the actual background.
RelativeLayout.LayoutParams frameLayoutParams = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
frameLayoutParams.addRule(RelativeLayout.CENTER_HORIZONTAL); // place frames in center of the view.
editedFrame.setLayoutParams(frameLayoutParams);
newFrame.addView(breakingNewsLayout); // add the breaking news layout to this view!
newFrame.addView(editedFrame);
The problem is specifically triggered from the second to last line newFrame.addView(breakingNewsLayout) That line triggers the exception. The breakingNewsLayout is another relative layout that I would like to add to newFrame. I would appreciate any knowledge on how to get this to work. I never ran into a problem when nesting layouts before, but for some reason, this is really not playing nice.
Here is the code that creates the breakingNewsLayout:
private void createBreakingNewsLayout()
{
breakingNewsLayout = new RelativeLayout(vidRipperService.getBaseContext()); // create the new breaking new layout.
breakingNewsLayout.setElevation(5);
breakingNewsLayout.setPadding(0,0,0,15);
breakingNewsLayout.setBackgroundColor(ContextCompat.getColor(vidRipperService, R.color.transparent)); // ensure that the background is transparent.
// MATCH_PARENT for both width and height so that banner is shown on the frame for the video.
RelativeLayout.LayoutParams breakingNewsParams = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
breakingNewsParams.setMargins(0,50,0,0); // todo: ensure that the margin is 50dp not pixels!
breakingNewsParams.addRule(RelativeLayout.CENTER_HORIZONTAL);
breakingNewsLayout.setLayoutParams(breakingNewsParams); // set the layout params for the breaking news layout.
// set all of the text view attributes.
TextView liveBannerText = getLiveBannerText();
TextView breakingNewsTime = getBreakingNewsTime();
TextView breakingNewsHeadline = getBreakingNewsHeadline(breakingNewsTime.getId()); // headline goes about the breaking news time.
TextView breakingNewsBanner = getBreakingNewsBanner(breakingNewsHeadline.getId()); // banner goes above the breaking news headline
TextView viddyWatermarkText = getViddyWatermarkText(breakingNewsHeadline.getId()); // viddy watermark goes above the breaking news headline.
TextView breakingNewsDescription = getBreakingNewsDescription(breakingNewsTime.getId()); // breaking news description goes to the end of the breaking news time
// Add all of the views for the breaking news layout.
breakingNewsLayout.addView(liveBannerText);
breakingNewsLayout.addView(breakingNewsBanner);
breakingNewsLayout.addView(viddyWatermarkText);
breakingNewsLayout.addView(breakingNewsHeadline);
breakingNewsLayout.addView(breakingNewsTime);
breakingNewsLayout.addView(breakingNewsDescription);
}
maybe you should remove breakingNewsLayout before you add it:
((ViewGroup) breakingNewsLayout.getParent()).removeView(breakingNewsLayout);
I figured it out! After extensive researching and testing the reason I was getting this issue was because I was attempting to reuse the breakingNewsLayout when creating a new frame. I have x amount of frames and I needed to generate the breakingNewsLayout every single time I wanted to apply the layout to the frame. Since I was trying to reuse the layout that I have already added, the layout already has a parent and thus the exception above was called.
Apologies for the question and any lack of details.
Here's a picture of what I want to do:
where all the pictures are different and I could have between 2-10.
The code I have now is:
(flag is # of pictures)
(picUris[] is my array of Uri's)
RelativeLayout imgLayout = (RelativeLayout) findViewById(R.id.RelativeLayoutPictures);
for (int i = 0; i < flag; i++)
{
ImageView iv = new ImageView(this);
iv.setImageURI(picUris[i]);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT);
lp.setMargins(50*i, 50*i, 0, 0);
lp.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
lp.addRule(RelativeLayout.ALIGN_PARENT_TOP);
imgLayout.addView(iv, lp);
}
and the result:
The problems are that it's getting resized and doesn't get cut off by the screen like I want, and there's something weird going on at the bottom.
Why not using the Stackview? basically it will achieve the exact smae result without making you creating the view progrimatically....you don't have to re-invent the wheel...
where all the pictures are different and I could have between 2-10
I think you should use LayerDrawable and offsetting each layer by for example setLayerInset. Or creating all of the background in xml and set it to your viewgroup. I do not recommend you use FrameLayout and RelativeLayout because they both use much RAM in your situation.
So I've tried my best but I have not found anything close to what I would like. I would like to know if this is possible without making 50 instances in my xml file. What I think i've come close to though:
ArrayList<Bitmap> bitmapArray = new ArrayList<Bitmap>();
for(int i=0;i<50;i++){
bitmapArray.add(Bitmap.createBitmap(Bmp1,(int) image.getX(),(int) image.getY(), bullpick.getWidth(), bullpick.getHeight()));
bulletArray[i].setImageBitmap(bitmapArray.get(i));
}
I've also tried making an ImageView array of one imageView but that would only leave me with one imageview. Any help is much appreciated!
Edit: For anyone who doesn't know what I'm talking about, i'm trying to make an array of 50 imageviews of the same image, but anything that would end up with an array of 50 images would be what I'm after. Thanks!
Put your image in drawable folder.
Then create a simple loop:
ArrayList<ImageView> imageViews= new ArrayList<ImageView>();
for (int i = 0; i < 50; i++) {
ImageView imageView = new ImageView(getApplicationContext());
imageView.setImageResource(R.drawable.yourimage);
imageViews.add(imageView);
}
This would create an arraylist of 50 imageviews.
I am doing an pageindex, and the current page should be highlighted with a arrow image (imageview).
The index is a RelativeLayout with 25 textviews added to it:
for (int i = 0; i < 25; i++) {
TextView tv = new TextView(this);
tv.setText(Integer.toString(i+1));
tv.setGravity(Gravity.CENTER);
int id = 2000+i;
tv.setId(id);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.FILL_PARENT);
if(i==0)
params.addRule(RelativeLayout.ALIGN_PARENT_LEFT, RelativeLayout.TRUE);
else
params.addRule(RelativeLayout.RIGHT_OF, prevViewId);
prevViewId = id;
rl.addView(tv,params);
}
And when the page changes I do something like this:
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.ALIGN_BOTTOM, 2000+i);
params.addRule(RelativeLayout.ALIGN_RIGHT, 2000+i);
params.addRule(RelativeLayout.ALIGN_LEFT, 2000+i);
arrowImageView.setLayoutParams(params);
rl.requestLayout();
rl.invalidate();
Everything looks correct, I can place the arrow at arbitrary page at "start up", but the arrow wont move when page is changed. I have debuged and verified that the code is run and everything looks correct, but still the arrow is stuck in the first position. If I force delete and add a new imageview instead of updating the LayoutParams the arrow will disappear totally.
I have the same problem.. I also want to move my views around at run-time inside a reference layout. So if anyone ca help that would be awesome.
What i believe is happening above is that the arrow IS having its location changed, however it doesn't get updated to the screen. Correct me if I'm wrong, please, this is just my guess as I am too having the same problem.
-edit-
After some messing around I've found what works for me is to remove first then add.
rl.removeView(tv);
rl.addView(tv,params);
-edit-
also, u can save the params for the moving view into a unique variable so that way all ude have to do is change the margins...
for example: instead of params, have it be its own name "arrowParams"
then to move it ude just need: arrowParams.leftMargin = 2000+i; and so on...