I have a thread that call a function in my main activity that should add an image to my layout at a certain position.. When i call my function all works properly but my layout's parameter (margin in my case) resets when i call:
myLayout.addView(newImage);
That's my function that my thread calls:
public void createImageAt(Point location) {
final ImageView newImage = new ImageView(this);
final RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(90, 90);
params.leftMargin = location.x;
params.topMargin = location.y;
newImage.setImageResource(R.drawable.image);
newImage.setLayoutParams(params);
final RelativeLayout myLayout = (RelativeLayout) findViewById(R.id.gameLayout);
myLayout.post(new Runnable() {
#Override
public void run() {
myLayout.addView(newImage);
}
});
}
My problem is that i have to slide my layout by moving the leftMargin, and when i call the function wrote above the margin jump back to 0 even if it was at -200px
If the problem, that the state does not saves, make newImage global variable and reuse it. Just use myLayout.addView(newImage); and myLayout.remove(newImage);
Related
I've been browsing the entire internet, but I could not find any answer to this question. I want to create a background, some image buttons, along with a bunch of moving graphics (circles). Since I do not know how to overwrite a xml layout with moving graphics, I chose to customly create my view, draw the background, the imageButtons and the circles (2D graphics).
public class GameView extends View implements UtilConstants
since I extended the View class, I had to call the super class constructor in my constructor
GameView(Context context) {
super(context);
this.context = context;
this.paint = new Paint();
}
and to implement the onDraw method, which acts like the java paintComponent
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas); // necessary for some reason
setGridBackground(); // sets the background
paint.setColor(Color.parseColor("#FF0000"));
canvas.drawCircle(this.x += 10, 300, 20, paint); //moves my graphics (ball) within the screen
drawScoreInLeftUpperCorner(canvas, 20); // paints a string text on the screen
setAbilitiesImages(); // places some imageButtons
try {
Thread.sleep(THREAD_REFRESH_RATE_MS);
} catch (InterruptedException ex) {
System.out.println(ex);
}
invalidate();
}
Now, to get to my problem:
I do not know how to set those ImageButtons !!! I am trying
private void setAbilititesImages() {
ImageButton imageButton = new ImageButton(this.context); // is this ok to put the argument this.context??
imageButton.setLayoutParams(new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT));
imageButton.setImageResource(R.drawable.monster); // set my resource
RelativeLayout relativeLayout = findViewById(R.id.in_game_layout); // what is the purpose of this???
if (relativeLayout != null) { // it never enters this if, relativeLayout is always null
relativeLayout.addView(imageButton);
}
}
Aaaaand the image button never shows up...why is it necessary to use Relative/Linear layouts? That R.id.in_game_layout I created is just an empty RelativeLayout xml. Can't I just use something like
imageButton.setImageResource(R.drawable.monster); // set my resource
imageButton.setBounds(.....);
(View)this.add(imageButton); ???
ImageButton requires a parent view to be hosted in it. The parent View can be a RelativeLayout, a linearlayout or a ConstraintLayout.
In your case, the instance relativeLayout is always null because you not specify the view parent in which you do findViewById.
You should make something like :
RelativeLayout relativeLayout = view.findViewById(R.id.in_game_layout);
You need to add layout param to your parent Relative layout also to display your Image button appropriately.
Example
RelativeLayout relativeLayout = findViewById(R.id.relativeLayout);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
ImageButton imageButton = new ImageButton(this);
imageButton.setImageDrawable(getResources().getDrawable(R.drawable.ic_launcher_background,null));
relativeLayout.addView(imageButton,params);
I am using the Slider of Material component:
https://github.com/material-components/material-components-android/blob/master/docs/components/Slider.md
I am trying to display a label when the thumb is moving, which seem to be supported with the labelFormatter attribute.
here is what my code looks like:
Slider s = new Slider(context);
s.setLabelFormatter(new Slider.LabelFormatter() {
#NonNull
#Override
public String getFormattedValue(float value) {
return "MY STRING";
}
});
When I go line by line with debugger it goes through this function:
private void drawLabelText(#NonNull Canvas canvas, int width, int top) {
labelTextPaint.getTextBounds(labelText, 0, labelText.length(), labelTextBounds);
int left = trackSidePadding + (int) (thumbPosition * width) - labelTextBounds.width() / 2;
canvas.drawText(labelText, left, top - labelTextTopOffset - thumbRadius, labelTextPaint); }
but no text is displayed only the slider...
I am kind of new in androïd and I am surely missing something.
Thanks for help :)
EDIT 1:
Here is the whole code simplified :
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
CoordinatorLayout layout = new CoordinatorLayout(this);
setContentView(layout);
// I am Using Coordinator Layout for current activity so...
CoordinatorLayout.LayoutParams layoutParams = new CoordinatorLayout.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
//Setting gravity to CENTER
layoutParams.gravity = Gravity.CENTER;
Slider slider = new Slider(this);
slider.setLabelFormatter(new Slider.LabelFormatter() {
#NonNull
#Override
public String getFormattedValue(float value) {
return "MY STRING";
}
});
layout.addView(slider, layoutParams);
}
But still not working ...
output result
https://youtu.be/obV4K-Nxu-0
EDIT 2:
Updating Material component from version: '1.2.0-alpha02' to version: '1.2.0-alpha05' fixed the issue.
Actually i wanted to comment but because of Reputation Constraints i couldn't,
Looks like you are adding a view programatically in your activity. Here i have implemented new MaterialComponent Slider with LabelFormatter
ViewGroup group = findViewById("YOUR_ACTIVITY_LAYOUT");
// I am Using Coordinator Layout for current activity so...
CoordinatorLayout.LayoutParams layoutParams = new CoordinatorLayout.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
//Setting gravity to CENTER
layoutParams.gravity = Gravity.CENTER;
Slider slider = new Slider(this);
slider.setLabelFormatter(new Slider.LabelFormatter() {
#NonNull
#Override
public String getFormattedValue(float value) {
return "MY STRING";
}
});
group.addView(slider, layoutParams);
}
And then there you go...
In my layout I have a GridView containing 4 custom ImageViews. I'm setting GridView's visibility to invisible until all ImageViews are resized at first but when the GridView is shown, there's a short blink with ImageViews still unchanged.
blink for a split second
views are resized in a moment
Each ImageView creates separate listener in order to scale its size:
//Setting new params as half of parent's size and increasing counter
if (getViewTreeObserver().isAlive()) {
final ViewTreeObserver viewTreeObserver = getViewTreeObserver();
viewTreeObserver.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
#Override
public boolean onPreDraw() {
getViewTreeObserver().removeOnPreDrawListener(this);
View parent = (View) getParent();
int dimension = Math.min(parent.getWidth(), parent.getHeight()) / 2;
mThisImageView.setLayoutParams(new AbsListView.LayoutParams(dimension, dimension));
ResizeCounter.setCounter(ResizeCounter.getCounter() + 1);
return true;
}
});
}
//Activity listens to the moment when all ImageViews have been resized
ResizeCounter.addCounterListener(new OnResizeCounterChangeListener() {
#Override
public void onResizeCounterChanged() {
if (ResizeCounter.getCounter() == 4) {
mAnswerGridView.setVisibility(View.VISIBLE);
}
}
});
I've also tried to resize them in onGlobalLayout method (same result) and to override onMeasure method (parent View is still null at this point).
I suspect that it's too late to change views in onPreDraw() but is there a method that can be called earlier inside which I can be sure that all views have been measured?
Try to call mAnswerGridView.requestLayout() before mAnswerGridView.setVisibility(View.VISIBLE);
This may not work because as it's stated at Android Developers
This will schedule a layout pass of the view tree.
So you may better force relayout:
relayoutChildren(View view) {
view.measure(
View.MeasureSpec.makeMeasureSpec(view.getMeasuredWidth(), View.MeasureSpec.EXACTLY),
View.MeasureSpec.makeMeasureSpec(view.getMeasuredHeight(), View.MeasureSpec.EXACTLY));
view.layout(view.getLeft(), view.getTop(), view.getRight(), view.getBottom()); }
I've created a handler that schedules setting visibility right after calling requestLayout.
Works well in this case.
ResizeCounter.addCounterListener(new OnResizeCounterChangeListener() {
#Override
public void onResizeCounterChanged() {
if (ResizeCounter.getCounter() == 4) {
mAnswerGridView.requestLayout();
Handler handler = new Handler();
handler.post(new Runnable() {
#Override
public void run() {
mAnswerGridView.setVisibility(View.VISIBLE);
}
});
}
}
});
I have written this code that loads an image to in ImageView widget:
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.gallery);
i = (ImageView)findViewById(R.id.imageView1);
new get_image("https://www.google.com/images/srpr/logo4w.png") {
ImageView imageView1 = new ImageView(GalleryActivity.this);
ProgressDialog dialog = ProgressDialog.show(GalleryActivity.this, "", "Loading. Please wait...", true);
protected void onPreExecute(){
super.onPreExecute();
}
protected void onPostExecute(Boolean result) {
i.setImageBitmap(bitmap);
dialog.dismiss();
}
}.execute();
}
bu now, I want to load several images. for this I need create image views dynamically but i don't know how...
I want run my code inside a for loop:
for(int i;i<range;i++){
//LOAD SEVERAL IMAGES. READ URL FROM AN ARRAY
}
my main problem is creating several ImageViews inside a loop dynamically
you can modify the layout , image resource and no of images (may be dynamic as well) according to your requirement...
LinearLayout layout = (LinearLayout)findViewById(R.id.imageLayout);
for(int i=0;i<10;i++)
{
ImageView image = new ImageView(this);
image.setLayoutParams(new android.view.ViewGroup.LayoutParams(80,60));
image.setMaxHeight(20);
image.setMaxWidth(20);
// Adds the view to the layout
layout.addView(image);
}
You can use this code to create ImageViews
ImageView image = new ImageView(this);
LinearLayout.LayoutParams vp = new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
image.setLayoutParams(vp);
image.setMaxHeight(50);
image.setMaxWidth(50);
// other image settings
image.setImageDrawable(drawable);
theLayout.addView(image);
where theLayout is the layout you want to add your image views to.
For more customization check out the dev page, where all the possible options are listed.
If your requirement is show in List or Gridview then you should go for Lazy Loading List or grid.
Please go through the below link.
https://github.com/thest1/LazyList
https://github.com/abscondment/lazy-gallery
Try this
rootLayout = (LinearLayout) view1.findViewById(R.id.linearLayout1);
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
params.gravity = Gravity.CENTER_VERTICAL;
params.setMargins(0, 0, 60, 0);
for(int x=0;x<2;x++) {
ImageView image = new ImageView(getActivity());
image.setBackgroundResource(R.drawable.ic_swimming);
rootLayout.addView(image);
}
I have a RelativeLayout completely created within java, not using xml layout.
I have a few buttons on the left if my screen. I want to click on one button and show a default image from my res/drawable next to the button and make it disappear again on second click.
What I have tried was toggling the visibility but my onClick() raises a FATAL EXCEPTION, NullPointer Exception.
This is my code so far. Hardcoded the image shows right when I set picview.setVisibility(View.INVISIBLE); by hand. What I am doing wrong in the onClick() ?
private ImageView picview;
//*snip* loads of other code
//Show Image Button
ImageButton show_pic = new ImageButton(this);
show_pic.setBackgroundColor(Color.WHITE);
show_pic.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v) {
if(picview.getVisibility() == View.INVISIBLE)
{
picview.setVisibility(View.VISIBLE);
}
else if (picview.getVisibility() == View.VISIBLE)
{
picview.setVisibility(View.INVISIBLE);
}
}
});
params = new RelativeLayout.LayoutParams(40, 40);
params.topMargin = 10;
params.leftMargin = 10;
params.addRule(RelativeLayout.BELOW, button2_id);
rl.addView(show_pic, params);
//Imageview loaded from drawable
ImageView picview = new ImageView(this);
params = new RelativeLayout.LayoutParams(200, 400);
params.topMargin = 0;
params.leftMargin = 30;
params.addRule(RelativeLayout.RIGHT_OF, button2_id);
picview.setImageResource(R.drawable.my_image);
picview.setVisibility(View.INVISIBLE);
rl.addView(picview, params);
this.setContentView(rl);
You are accidentally creating two copies of picview. Shorten this line:
ImageView picview = new ImageView(this);
To:
picview = new ImageView(this);
(Your field variable private ImageView picview; never changed from null, so when you clicked your Button you see the NullPointerException...)
change
show_pic.setOnClickListener(new OnClickListener() to
show_pic.setOnClickListener(new View.OnClickListener()