I'm wondering what would be the best solution to get to the result shown below.
Here is what i've found so far:
an ImageView for the forest and a transparent surfaceView (to handle touch) on which I would draw the rectangles?
Or...
Just One SurfaceView with the image set as background and rectangles directly drawn on...?
For those 2 I've already chosen a RelativeLayout.
Which of those 2 would be the most efficient and easiest to do?
Or maybe there is another way which I haven't think about.
In any case thanks for your advice, here is what I tend to...
I've implemented this by placing the image in a RelativeLayout (FrameLayout would work too), and then adding each outlined view programatically. If you know the x and y origin (perhaps as a ratio to the image) and the size for each area, you can easily inflate each view/area (with a black border, transparent center), make it clickable and set a listener, and then set it's origin by adjusting it's margins. You may want to perform all of this after the image has finished laying out:
I put this in onActivityCreated of my Fragment, but other lifecycle methods would work too...
ViewTreeObserver vto = image.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
if (image.getMeasuredHeight() > 0) {
addHotSpots();
ViewTreeObserver obs = image.getViewTreeObserver();
obs.removeGlobalOnLayoutListener(this);
}
}
});
And this is how I actually place all the hotspots/areas:
protected void addHotSpots() {
HotSpot[] hotSpots = res.hotspots;
for (HotSpot hs : hotSpots) {
addHotSpotToImage(hs);
}
private void addHotSpotToImage(HotSpot hs) {
int height = image.getMeasuredHeight();
int width = image.getMeasuredWidth();
//this piece will probably be different for you
//depending on what you know about the area's intended size/position
double hsHeightRatio = hs.lr.y - hs.ul.y;
double hsWidthRatio = hs.lr.x - hs.ul.x;
double leftMargin = hs.ul.x * width;
double topMargin = hs.ul.y * height;
double hsHeight = height * hsHeightRatio;
double hsWidth = width * hsWidthRatio;
LayoutInflater vi = (LayoutInflater) image.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View newSpot = vi.inflate(R.layout.question_hotspot, null);
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams((int) hsWidth, (int) hsHeight);
newSpot.setTag(hs.key);
newSpot.setFocusable(true);
newSpot.setClickable(true);
newSpot.setFocusableInTouchMode(true);
newSpot.setOnTouchListener(this);
params.topMargin = (int) topMargin;
params.leftMargin = (int) leftMargin;
image.addView(newSpot, params);
}
Related
in the project, I tried adding a View object dynamically in a RelativeLayout
ImageView card = new ImageView(this);
card.setImageResource(R.drawable.card);
RelativeLayout.LayoutParams layoutParams =
new RelativeLayout.LayoutParams(225, 315);
layoutParams.addRule(RelativeLayout.CENTER_VERTICAL);
layoutParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT);
layoutParams.rightMargin = 40;
parent.addView(card, layoutParams);
after a while, when I tried to get the location of this View, no method works.
As I found in Studio's debug view, the View's layoutparams and all its attrs like mLeft... got the value 0.
So how could I solve the problem? thanks a lot.
It might be because you tried to get position before onLayout has happened.
You might try something like this:
ViewTreeObserver vto=view.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener(){
#Override public void onGlobalLayout(){
int [] location = new int[2];
view.getLocationOnScreen(location);
x = location[0];
y = location[1];
view.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
}
Also check how to get view's position in coordinates?
You can use these code to get the location:
int loc[]=new int[2];
card.getLocationOnScreen(loc);
int x=loc[0];
int y=loc[1];
If you want to get the location, you have to wait for the View to complete the measurement.
Simple and best way to find a location of view on screen.
view.post(() -> {
xPosition = view.getX());
yPosition = view.getY();
};
view.post() is used because of that if you try to get view location onCreate() method without using post then you get (0,0) because of that view takes few millisecond to inflate on the screen.
Using the Data Binding Library in Android to get location of a view.
private fun getViewLocation(){
val loginBinding = ActivityLoginBinding.inflate(layoutInflater)
val locationX = loginBinding.forgotPasswordBtn.x
val locationY = loginBinding.forgotPasswordBtn.y
// locationX and locationY are returned as Float values
}
I am confused on when to use setWidth, and setHeight? It usually don't work.
What always work is setLayoutParams.
This will work.
sampleButton = new Button(this);
sampleButton.setLayoutParams(new LinearLayout.LayoutParams(65, 65));
This will not work.
sampleButton = new Button(this);
sampleButton.setHeight(65);
sampleButton.setWidth(65);
Or maybe there are some initialisation for this code to work?
So, just looked at the Button's source code (which is a subclass of TextView):
http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.1_r2/android/widget/TextView.java#TextView.setHeight%28int%29
here is the method for setHeight
public void setHeight(int pixels) {
mMaximum = mMinimum = pixels;
mMaxMode = mMinMode = PIXELS;
requestLayout();
invalidate();
}
now in the onMeasure method, mMaximum and mMaxMode are used here
int unpaddedHeight = height - getCompoundPaddingTop() - getCompoundPaddingBottom();
if (mMaxMode == LINES && mLayout.getLineCount() > mMaximum) {
unpaddedHeight = Math.min(unpaddedHeight, mLayout.getLineTop(mMaximum));
}
It looks like the setheight doesn't really overwrite the internal height parameters, more just sets flags for layout.
Changing the layout params (which are what are actually referenced when the view is laying itself out) seem to inform the view that it actually needs to be that hight
TLDR; setHeight has more to do with the line height of the text than the height of the view
Alright I'm trying to build an activity that has a horizontal scrollview, that the user can swipe through, to view different "pages". My train of thought is these "pages" will be views. The following is a mockup of my idea (to mess around to see if it works)
I've experimented with this as follows:
My content view is set to the the scrollview. (unsure if this is an incorrect approach)
I create the scrollview, and place a view into it as follows:
private void setupScrollView()
{
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics ();
display.getMetrics(outMetrics);
float density = getResources().getDisplayMetrics().density;
float dpHeight = outMetrics.heightPixels / density;
float dpWidth = outMetrics.widthPixels / density;
int width = (int)MeasureUtils.convertDpToPixel(dpWidth, getApplicationContext());
int height = (int)MeasureUtils.convertDpToPixel(dpHeight, getApplicationContext());
_scrollView = new HorizontalScrollView(getApplicationContext());
_scrollView.setBackgroundColor(Color.CYAN);
_scrollView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
Log.i("DEBUG", "Screen dp width = " + dpWidth + " screen dp height = " + dpHeight);
TextView view = new TextView(getApplicationContext());
view.setBackgroundColor(Color.RED);
view.setText("TEST");
view.setX(0); // Start at the left of the scrollview.
view.setWidth(width); // Size it so that it fills to the right of the scrollview.
TextView view2 = new TextView(getApplicationContext());
view2.setBackgroundColor(Color.GREEN);
view2.setText("TEST2");
view2.setX(width); // Start the second "page/view" offscreen to the right where i can scroll to it
view.setWidth(width); // Fill the screen width
LinearLayout layout = new LinearLayout(getApplicationContext());
layout.setBackgroundColor(Color.MAGENTA);
layout.addView(view);
layout.addView(view2);
_scrollView.addView(layout);
}
The idea above is that I will see a view, that takes up the screen, representing a page. This view should be "RED" in color. I can then scroll horizontally to the right and see the second view (view2) representing the next page. This view should be "GREEN" in color. This does not happen. I end up seeing what looks like 1/3rd or 1/2 of my screen being view1, the linearlayout taking up almost the whole screen (a bit of a gap to the right edge where the CYAN from the scrollview bleeds through).
Am I approaching this the wrong way, and/or is it possible to make this work the way I'm going at it?
You probably do not want to use a horizontalscroll view to create "pages".
Try looking at PageViewer
This automatically builds in all the sywpe and inflating logic for you.
Basically you will get a call to inflate a certain page. There you can then create your view (dynamically if you wish) and then just return the root to be rendered.
Alright I've figured out what I was doing wrong, and it turned out to be something very small...
The complete code is here:
private void setupScrollView()
{
Display display = getWindowManager().getDefaultDisplay();
DisplayMetrics outMetrics = new DisplayMetrics ();
display.getMetrics(outMetrics);
float density = getResources().getDisplayMetrics().density;
float dpHeight = outMetrics.heightPixels / density;
float dpWidth = outMetrics.widthPixels / density;
int width = (int)MeasureUtils.convertDpToPixel(dpWidth, getApplicationContext());
int height = (int)MeasureUtils.convertDpToPixel(dpHeight, getApplicationContext());
_scrollView = new HorizontalScrollView(getApplicationContext());
_scrollView.setBackgroundColor(Color.CYAN);
_scrollView.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
Log.i("DEBUG", "Screen dp width = " + dpWidth + " screen dp height = " + dpHeight);
TextView view = new TextView(getApplicationContext());
view.setBackgroundColor(Color.RED);
view.setText("TEST");
view.setX(0);
view.setWidth(width);
view.setHeight(height - 50);
TextView view2 = new TextView(getApplicationContext());
view2.setBackgroundColor(Color.GREEN);
view2.setText("TEST2");
view2.setX(0);
view2.setWidth(width);
view2.setHeight(height - 50);
LinearLayout layout = new LinearLayout(getApplicationContext());
layout.setBackgroundColor(Color.MAGENTA);
layout.addView(view);
layout.addView(view2);
_scrollView.addView(layout);
}
This creates a horizontal scrollview programmatically, as I had, but the problem was that I was setting the second view to be "width" away, when it should be set to "0"as can be seen by:
view2.setX(0);
With that, I get 2 "views" that resemble pages in my scrollview that I can swipe through. Each taking up the whole page.
Hate having the code close and it being a simple fix that I missed :|
Hope this helps anyone else that tries to do it this way. I'm going to look into the PageViewer as Frank suggested.
I'm trying to make a dynamic grid layout, it being API 10+ is the part that's been making it slow going. I tried to make it wrap automatically.. but in the end found it easier just to try to force it into a grid pattern using coordinates. This script was working by itself when I did the positioning at time of creation, but now I am trying to loop through each item as a sort. So if one item is deleted, they all float back into a grid without a hole in the middle.
Problem is, it seems the layout parameters are only applying to the last object.
Here's some base variables and onCreate setup:
int screenWidth;
int screenHeight;
int distStep = 130;
int leftPad = 20;
int numCols;
int baseID = 0;
android.util.DisplayMetrics metrics = this.getResources().getDisplayMetrics();
screenWidth = metrics.widthPixels;
screenHeight = metrics.heightPixels;
numCols = (int) (screenWidth - leftPad) / distStep;
int scrRemain = screenWidth - ((numCols * distStep) + leftPad);
distStep += (int) scrRemain / numCols;
Then on to the main function for adding:
public void addObjToLayout() {
RelativeLayout relLay = (RelativeLayout) this.findViewById(R.id.mainWindow);
for(int i = 1; i <= currQuantity; i++){
TextView tv=new TextView(this);
tv.setTextSize(40);
tv.setId(baseID + i);
tv.setPadding(24, 4, 24, 4);
tv.setBackgroundColor(0x110000FF);
tv.setText(String.valueOf(baseID + i)); //Val for debugging
tv.setTextColor(0xFFFFFFFF);
relLay.addView(tv);
}
baseID += currQuantity;
sortLayout();
}
Then the sorting:
public void sortLayout() {
int leftNum = 20;
int topNum = 0;
for(int i = 1; i <= baseID; i++){
TextView tv= (TextView) this.findViewById(baseID);
MarginLayoutParams mp = new MarginLayoutParams(tv.getLayoutParams());
mp.setMargins(leftNum, topNum, 0, 0);
RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(mp);
tv.setLayoutParams(lp);
leftNum += distStep;
if(leftNum >= distStep * numCols){
leftNum = leftPad;
topNum += distStep;
}
}
}
What I am getting is all the textViews pile up in the top left corner, except the last one which is positioned exactly where it should be. So it seems in my head, the params object isn't applying until the loop ends or something.. but logically I don't see why.
As I said, this worked when I set the params at the get go, problem is mass updating them all at once. I am pretty new to android, so I hope I'm not just doing something stupid.
Thanks for your time
Margin means it will set a gap between the previous view and current view.
When you add view1, view2 and view3 to grid layout and if you remove view2 at some point of time, then the margin for view3 is set according to view1. So, it won't leave empty space in place of view2. Instead of removing view2 at run time, set the background for view2 as null and set the text as empty as below.
textView.setBackground(null);
textView.setText("");
So that the view is still available but looks as deleted.
Started looking into GridView using an extended baseAdapter. Looks promising:
For more (see #2):
http://www.mkyong.com/android/android-gridview-example/
I am trying to set padding of an ImageView. My code is below
private void createEpisodeView() {
float scale = this.getResources().getDisplayMetrics().density;
int padding = (int) (PADDING * scale + 0.5f);
rlItemsRoot = (LinearLayout) findViewById(R.id.rl_items_root);
for (int i = 0; i < GameLevels.TOTAL_EPISODES; i++) {
ImageView iv = new ImageView(this);
iv.setPadding(padding, padding, padding, padding);
iv.setBackgroundResource(R.drawable.icon_small);
rlItemsRoot.addView(iv);
}
}
But it has no effect. but when I set this in XML it looks fine.
A you noticed yourself you are using
iv.setBackgroundResource(R.drawable.icon_small);
This will set the Background for the ImageView. The Background Image will fill the whole view because it is behind all the content in the View.
Use
iv.setImageResource(R.drawable.icon_small);
instead.
Rather than setting
iv.setBackgroundResource(R.drawable.icon_small);
set
iv.setImageResource(R.drawable.icon_small);
and problem solved :)
If any body knows the reason please reply.