Problem with getting the id's of image view in Android? - android-imageview

I am implementing an application displaying images and messages obtained from .net server. For that I'm adding LinearLayout's with TextView and ImageView dynamically by using for loop.
At first I am getting messages and I'm adding them to the TextView with dummy images placed in ImageView:
for(int i = 0; i < messages.size(); i++) {
FrameLayout f1 = new FrameLayout(this);
LinearLayout l1 = new LinearLayout(this);
LinearLayout l2 = new LinearLayout(this);
im = new ImageView(this);
TextView tv = new TextView(this);
tv.setText(messages.get(i).getmessage());
im.setImageResource(R.drawable.person);
l1.addView(tv);
l2.addView(im);
f1.addView(l1);
f1.addView(l2);
((LinearLayout)findViewById(R.id.LinearlayoutMessage)).addView(f1);
}
After some time I am getting original images. My intention is to replace the dummy images with original ones. To achieve this I'm using imageview.getid() unfortunately I'm getting last id of the imageview. But I need to get each individual imageview id's.
What is the best way of changing dummy images with real ones?

Looks like you need to store each imageView id in a map from each message -> imageView like so:
Map<Message, Long> messageMapping = new HashMap<Message, Long>();
for(int i = 0; i < messages.size(); i++) {
FrameLayout f1 = new FrameLayout(this);
LinearLayout l1 = new LinearLayout(this);
LinearLayout l2 = new LinearLayout(this);
im = new ImageView(this);
TextView tv = new TextView(this);
//add mapping
messageMapping.put(messages.get(i), im.getId());
tv.setText(messages.get(i).getmessage());
im.setImageResource(R.drawable.person);
l1.addView(tv);
l2.addView(im);
f1.addView(l1);
f1.addView(l2);
((LinearLayout)findViewById(R.id.LinearlayoutMessage)).addView(f1);
}
Then when it comes time to lazy load your images into the existing imageViews you simply need to look up the imageView id reference by message mapping:
(Total guess of what your code could look like)
for(int i = 0; i < messages.size(); i++){
Image image = queryServerForImage(messages.get(i).getImageId());
ImageView imageView = ((ImageView)findViewById(messageMapping.get(messages.get(i))));
//some conversion & seteup may be needed to get image into proper format
imageView.setImageBitmap(image);
}
You may be able to do something similar with async tasks. You could span each one in the message ImageView creation loop with the associated resource id and having each asyc task update the ui from the network response.

Related

ImageView is not respecting the size of the CardView

I am trying to make some sort of gallery app. I would like to display images inside of a ScrollView inside a GridLayout so I used CardView for this and it looks like this:
But when I put ImageView inside each CardView, the CardView spreads and fills the whole ScrollView. Here's a preview:
The CardView is created programatically. Here's the code
fun CreateCardView(ItemCount: Int){
for (i in 1 until ItemCount){
/////////////////////CARD VIEW//////////////////////////////
val card_view = CardView(this)
card_view.radius = 8F
card_view.setContentPadding(8,8,8,8)
card_view.setCardBackgroundColor(Color.LTGRAY)
card_view.cardElevation = 8F
val param = GridLayout.LayoutParams()
param.rowSpec = GridLayout.spec(GridLayout.UNDEFINED, 1f)
param.columnSpec = GridLayout.spec(GridLayout.UNDEFINED, 1f)
card_view.layoutParams = param
val param2 = card_view.layoutParams as GridLayout.LayoutParams
param2.setMargins(10,10,10,10)
card_view.layoutParams = param2
subLayoutGrid?.addView(card_view)
////////////////////////END//////////////////////////////////////
///////////////////////IMAGEVIEW////////////////////////////////
val img = ImageView(this)
val imageparams = WindowManager.LayoutParams(
WindowManager.LayoutParams.WRAP_CONTENT,
WindowManager.LayoutParams.WRAP_CONTENT
)
img.layoutParams = imageparams
img.scaleType = ImageView.ScaleType.CENTER_CROP
img.setImageResource(R.drawable.animaleight)
card_view.addView(img)
////////////////////////END///////////////////////////
}
}
How can I put ImageView inside the CardView without filling the whole ScrollView?
I've already fixed my problem. I've tried to use a 40px x 40px Picture then it worked the way I want to. See the image:
It seems like when you use high resolution Picture, the app cant handle the populating of ImageView in GridLayout.

Screenshot of Mapbox map without displaying it

I need to display a few previews of addresses on the map on the same screen. To do that I'm going to display ImageViews with bitmaps instead of making multiple instances of MapView. But for that I need to find a way to capture these bitmaps.
I found snapshot function in MapboxMap (https://github.com/mapbox/mapbox-gl-native/issues/6062), but it requires displaying of the map.
val position = CameraPosition.Builder()
.target(addressLatLng)
.zoom(zoom)
.build()
mapboxMap.cameraPosition = position
mapboxMap.snapshot { bitmap: Bitmap ->
imageView.setImageBitmap(bitmap)
}
So, can I take a snapshot of the map without displaying it on the screen?
I've finally found the solution! The class I needed to use was MapSnapshotter.
val width = imageView.width
val height = imageView.height
val location = CameraPosition.Builder()
.target(LatLng(55.7558, 37.6173))
.zoom(16.0)
.build()
val options = MapSnapshotter.Options(width, height)
.withCameraPosition(location)
MapSnapshotter(context, options).start { snapshot ->
imageView.setImageBitmap(snapshot.bitmap)
}

Object detection from image using vision framework

I am trying to detect objects from a given image. From research I just found that we can detect and track an object for the videos using the following process:
private lazy var cameraLayer: AVCaptureVideoPreviewLayer = AVCaptureVideoPreviewLayer(session: self.captureSession)
private func tapGestureAction(recognizer: UITapGestureRecognizer)
{
highlightView.frame.size = CGSize(width: 200, height: 200)
highlightView.center = recognizer.location(in: view)
let originalRect = highlightView.frame
var convertedRect = cameraLayer.metadataOutputRectConverted(fromLayerRect: originalRect)
convertedRect.origin.y = 1 - convertedRect.origin.y
previousObservation = VNDetectedObjectObservation(boundingBox: convertedRect)
}
Can we have similar method like metadataOutputRectConverted for imageView? I am trying to detect the object rect whenever the user taps on that object. How can this be accomplished?
this method to convert the camera output rect ( topleft(0,0) to bottomright(0,1)) to the UI rect. So, I think you do not need to convert it

Adding Image to Xaml not rendering with given margin

for (int i = 0; i < length; i++)
{
Image img1 ;
img1 = null;
img1= new Image();
img1.Height = snhei;
img1.Width = snwid;
BitmapImage BitImg = new BitmapImage(new Uri("/Assets/midtail.png", UriKind.Relative));`
img1.VerticalAlignment = VerticalAlignment.Top;
img1.HorizontalAlignment = HorizontalAlignment.Left;
img1.Source = BitImg;
img1.Stretch = Stretch.Fill;
img1.Name = "mid" + i.ToString() ;
img1.Margin = new Thickness(image_width*i, 0, 0, 0);
stackp.Children.Add(img1);
}
after running i get first image at 0,0
then it is render the one image_width below
The problem is your container. The StackPanel will, as it name indicates, try to stack the images. Then you apply the margin, moving the picture farther away.
You have two solutions, depending on what you want:
If you just want the images to be displayed side by side, set the Orientation property of your StackPanel to Horizontal. Then, remove your line of code that sets the margin, since the positioning is automatically handled by the StackPanel
If you still want to position the pictures manually, then you have to use another type of container. Replace your StackPanel by a Canvas or a Grid.

while I scroll between the layout it takes too long to be able to scroll between the gallerie's pictures. Is there any way to reduce this time?

this is my first question here, though I've being reading this forum for quite a while. Most of the answers to my doubts are from here :)
Getting back on topic. I'm developing an Android application. I'm drawing a dynamic layout that are basically Galleries, inside a LinearLayout, inside a ScrollView, inside a RelativeLayout. The ScrollView is a must, because I'm drawing a dynamic amount of galleries that most probably will not fit on the screen.
When I scroll inside the layout, I have to wait 3/4 seconds until the ScrollView "deactivates" to be able to scroll inside the galleries. What I want to do is to reduce this time to a minimum. Preferably I would like to be able to scroll inside the galleries as soon as I lift my finger from the screen, though anything lower than 2 seconds would be great as well.
I've being googling around for a solution but all I could find until now where layout tutorials that didn't tackle this particular issue. I was hoping someone here knows if this is possible and if so to give me some hints on how to do so.
I would prefer not to do my own ScrollView to solve this. But if that is the only way I would appreciate some help because I'm not really sure how would I solve this issue by doing that.
this is my layout:
public class PicturesL extends Activity implements OnClickListener,
OnItemClickListener, OnItemLongClickListener {
private ArrayList<ImageView> imageView = new ArrayList<ImageView>();
private StringBuilder PicsDate = new StringBuilder();
private CaWaApplication application;
private long ListID;
private ArrayList<Gallery> gallery = new ArrayList<Gallery>();
private ArrayList<Bitmap> Thumbails = new ArrayList<Bitmap>();
private String idioma;
private ArrayList<Long> Days = new ArrayList<Long>();
private long oldDay;
private long oldThumbsLoaded;
private ArrayList<Long> ThumbailsDays = new ArrayList<Long>();
private ArrayList<ArrayList<Long>> IDs = new ArrayList<ArrayList<Long>>();
#Override
public void onCreate(Bundle savedInstancedState) {
super.onCreate(savedInstancedState);
RelativeLayout layout = new RelativeLayout(this);
ScrollView scroll = new ScrollView(this);
LinearLayout realLayout = new LinearLayout(this);
ArrayList<TextView> texts = new ArrayList<TextView>();
Button TakePic = new Button(this);
idioma = com.mateloft.cawa.prefs.getLang(this);
if (idioma.equals("en")) {
TakePic.setText("Take Picture");
} else if (idioma.equals("es")) {
TakePic.setText("Sacar Foto");
}
RelativeLayout.LayoutParams scrollLP = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.FILL_PARENT,
RelativeLayout.LayoutParams.FILL_PARENT);
layout.addView(scroll, scrollLP);
realLayout.setOrientation(LinearLayout.VERTICAL);
realLayout.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT,
LayoutParams.FILL_PARENT));
scroll.addView(realLayout);
TakePic.setId(67);
TakePic.setOnClickListener(this);
application = (CaWaApplication) getApplication();
ListID = getIntent().getExtras().getLong("listid");
getAllThumbailsOfID();
LinearLayout.LayoutParams TakeLP = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
realLayout.addView(TakePic);
oldThumbsLoaded = 0;
int galler = 100;
for (int z = 0; z < Days.size(); z++) {
ThumbailsManager croppedThumbs = new ThumbailsManager(Thumbails,
oldThumbsLoaded,
ThumbailsDays.get(z));
oldThumbsLoaded = ThumbailsDays.get(z);
texts.add(new TextView(this));
texts.get(z).setText("Day " + Days.get(z).toString());
gallery.add(new Gallery(this));
gallery.get(z).setAdapter(new ImageAdapter(this, croppedThumbs.getGallery(), 250, 175, true,
ListID));
gallery.get(z).setOnItemClickListener(this);
gallery.get(z).setOnItemLongClickListener(this);
gallery.get(z).setId(galler);
galler++;
realLayout.addView(texts.get(z));
realLayout.addView(gallery.get(z));
}
Log.d("PicturesL", "ListID: " + ListID);
setContentView(layout);
}
private void getAllThumbailsOfID() {
ArrayList<ModelPics> Pictures = new ArrayList<ModelPics>();
ArrayList<String> ThumbailsPath = new ArrayList<String>();
Pictures = application.dataManager.selectAllPics();
long thumbpathloaded = 0;
int currentID = 0;
for (int x = 0; x < Pictures.size(); x++) {
if (Pictures.get(x).walkname == ListID) {
if (Days.size() == 0) { Days.add(Pictures.get(x).day); oldDay = Pictures.get(x).day;
IDs.add(new ArrayList<Long>()); currentID = 0; }
if (oldDay != Pictures.get(x).day) {
oldDay = Pictures.get(x).day;
ThumbailsDays.add(thumbpathloaded);
Days.add(Pictures.get(x).day);
IDs.add(new ArrayList<Long>());
currentID++;
}
StringBuilder tpath = new StringBuilder();
tpath.append(Pictures.get(x).path.substring(0,
Pictures.get(x).path.length() - 4));
tpath.append("-t.jpg");
IDs.get(currentID).add(Pictures.get(x).id);
ThumbailsPath.add(tpath.toString());
thumbpathloaded++;
if (x == Pictures.size() - 1) {
Log.d("PicturesL", "El ultimo de los arrays, tamaƱo: " + Days.size());
ThumbailsDays.add(thumbpathloaded);
}
}
}
for (int y = 0; y < ThumbailsPath.size(); y++) {
Thumbails.add(BitmapFactory.decodeFile(ThumbailsPath.get(y)));
}
}
I had a memory leak on another activity when screen orientation changed that was making it slower, now it is working better. The scroller is not locking up. But sometimes, when it stops scrolling, it takes a few seconds (2/3) to disable itself. I just want it to be a little more dynamic, is there any way to override the listener and make it stop scrolling ON_ACTION_UP or something like that?
I don't want to use the listview because I want to have each gallery separated by other views, now I just have text, but I will probably separate them with images with a different size than the galleries.
I'm not really sure if this is possible with a listadapter and a listview, I assumed that a view can only handle only one type of object, so I'm using a scrollview of a layout, if I'm wrong please correct me :)
Also this activity works as a preview or selecting the pictures you want to view in full size and manage their values. So its working only with thumbnails. Each one weights 40 kb. Guessing that is very unlikely that a user gets more than 1000~1500 pictures in this view, i thought that the activity wouldn't use more than 40~50 mb of ram in this case, adding 10 more if I open the fullsized view. So I guessed as well most devices are able to display this view in full size. If it doesn't work on low-end devices my plan was to add an option in the app preferences to let user chop this view according to some database values.
And a last reason is that during most of this activity "life-cycle" (the app has pics that are relevant to the view, when it ends the value that selects which pictures are displayed has to change and no more pictures are added inside this instance of this activity); the view will be unpopulated, so most of the time showing everything wont cost much, just at the end of its cycle
That was more or less what I thought at the time i created this layout. I'm open to any sort of suggestion or opinion, I just created this layout a few days ago and I'm trying to see if it can work right, because it suits my app needs. Though if there is a better way i would love to hear it
PD: I've being toying to see how much it can actually draw. I managed to draw 530 galleries with 600 thumbnails on the same layout, the app is using 42 mb, and I don't have access to more memory to start my full sized view afterwards :( .I tried to do the same with 1000 but it throws OutOfMemory error, bitmap size exceeds vm budget. Is there any way to make more memory availeable on high-end devices? Or should I try to figure out a way not to draw everything at once? Would the listview work for more than one type of object?
Thanks
Mateo
Why not make your galleries items of a listview? That way you won't have to inflate all of them immediately and can the advantage of the listview recyling mechanism. Some of the slowness you are seeing might be coming from very heavy memory usage. Galleries aren't exactly light widgets so you might be seeing pauses from heavy GC activity once you stop scrolling. ListView with an adapter would also allow you to lazily bind the Galleries to the list, such that during a fling you aren't doing the expensive binding of the galleries.