I'm new to Android and I'm trying to find out how to do that:
- I have an activity with a ScrollView and inside it I have a LinearLayout (R.id.my_layout)
- I nedd to add TextView programmatically so I'm doing this:
I load the main XML layout via seContentView, I refer to my LinearLayout inside the ScrollView as "mLayout" and so on.
I load a list of names from a file and with a function called populateList()I do:
private void populateList() {
try {
for (final String team : mTeams) {
rCount++;
addRow(team);
}
}
The addRow() method just create a new LinearLayout (mRow), a TextView, 2 Button, add the TextView and the 2 Buttons to the LinearLayout, and then I use addView to add the new mRow to the mLayout.
Everything is working fine, but the ScrollView is shown only when i finished creating the list (so when the populateList() ends). What I would like to do is to show the rows one by one in sequence to give the activty a better look and a bit of animation.
Is there a way to do this?
I hope i was able to explain it :-)
Thank you
new Thread(new Runnable() { // i am creating the new thread
#Override
public void run() {
// so call populateList() function here
}
}).start();
and for your addRow(String string) method the place you call View.addView(); edit it this way and place the following code in your addRow(String string) method
View.post(new new Runnable() {// view here is mlayout the scrollView.
#Override
public void run() {
mlayout.addView(yourview); // note yourview should be final,
//eclipse might help you with that
}
});
remember to declare mlayout globally, so you do not have to attach final
Related
I'm having a very strange problem. Let me first describe the structure of the views:
MainActivity
CoordinatorLayout
AppBarLayout
CollapsingToolbarLayout
FloatingActionButton
ToolBar
NestedScrollView
TableLayout
TextView (many)
Button (optional)
What I'm trying to do is replacing the one NestedScrollView object with another according to user actions. I have created the following method for this:
public void switchTableGroup(final TableGroup newTG){
final NestedScrollView removeNSV = currentNSV;
Thread switchView = new Thread(){
public void run(){
mainCoordinatorLayout.removeView(removeNSV);
mainCoordinatorLayout.addView(newTG.getNestedScrollView());
}
};
runOnUiThread(switchView);
this.currentTG = newTG;
this.currentNSV = newTG.getNestedScrollView();
}
(note that the TableGroup is a non-graphical object for my internal data structure) This works fine as long as there is at least one Button object in the underlying TableLayout. If there is no Button object present, the old NestedScrollView is removed and the new one is written into currentNSV and added to the CoordinatorLayout, but somehow not invisible. With some dirty code this problem can be solved:
public void switchTableGroupDirty(final TableGroup newTG){
final NestedScrollView removeNSV = currentNSV;
Thread switchView = new Thread(){
public void run(){
mainCoordinatorLayout.removeView(removeNSV);
mainCoordinatorLayout.addView(newTG.getNestedScrollView());
}
};
runOnUiThread(switchView);
this.currentTG = newTG;
this.currentNSV = newTG.getNestedScrollView();
Thread doItAgain = new Thread(){
public void run(){
mainCoordinatorLayout.removeView(newTG.getNestedScrollView());
mainCoordinatorLayout.addView(newTG.getNestedScrollView());
}
};
runOnUiThread(doItAgain);
}
I don't want to depend on doing something twice, is there some specific command to force the CoordinatorLayout to redraw itself? I have already tried invalidate() and refreshDrawableState() on the CoordinatorLayout object, but this didn't help. Also spent a lot of time on trying various combinations, with sleeping etc. You can also imagine it took quite some time to isolate that the presence of the Button was the key factor to the success of the normal method...
Help is greatly appreciated.
I have a custom component that extends RelativeLayout which in turns holds a GridLayout(named mFormLayout). I have a public method that adds two spinners with their proper adapter source and an imageview which acts as a button to remove rows.
public class EditableTwinSpinnerGridForm extends EditableGridForm
{
public void addTwinSpinnerRow(final Locale.MapKey spinner1DefVal, final Locale.MapKey spinner2DefVal)
{
Spinner spinner1 = createSpinner(mTSP.getFirstSpinnerRes(), spinner1DefVal.getId());
spinner1.setOnItemSelectedListener(mTSP.getIsl());
Spinner spinner2 = createSpinner(mTSP.getSecondSpinnerRes(), spinner2DefVal.getId());
ImageView rmvBtn = createRemoveBtn();
mFormLayout.addView(spinner1);
mFormLayout.addView(spinner2);
mFormLayout.addView(rmvBtn);
}
}
For some reason, this method works when I am adding rows from a call to onCreate in an activity, but when I am calling this method after the activity is created(from an onclicklistener) the Spinners are either not there or only one of them shows up. They do take the space because I see the row and the removable image view.
I have also noticed that when I focus on a EditText in the same activity and the keyboard pops up, the added spinners show up when I press back to remove the keyboard.
Here's the code I use to create a spinner :
protected Spinner createSpinner(Integer spinnerSrc, String defaultSpinnerValue)
{
Spinner spinner = new Spinner(mCtx, Spinner.MODE_DIALOG);
// Setting the bg color to the containing color to remove the spinner arrow.
spinner.setBackgroundResource(R.color.container_bg);
SparseArray<Phrase> map = Locale.getInstance().getMap(spinnerSrc);
PhraseArrayAdapter adapter = createSpinnerFromMap(spinnerSrc);
spinner.setAdapter(adapter);
if (defaultSpinnerValue.equals(Utilities.EMPTY_STRING) || defaultSpinnerValue.isEmpty())
{
throw new IllegalStateException();
}
else
{
Utilities.getInstance().setMapSpinnerPosByValue(map, defaultSpinnerValue, spinner);
}
adapter.setDropDownViewResource(R.layout.editable_spinner_dropdown_item);
setSpinnerLayoutParams(spinner);
return spinner;
}
protected void setSpinnerLayoutParams(Spinner spinner)
{
GridLayout.LayoutParams lp = createDefaultGridParams();
lp.setGravity(Gravity.FILL_HORIZONTAL);
lp.width = 250;
lp.rightMargin = 0;
spinner.setLayoutParams(lp);
}
The code works when the activity is loaded so I'm a bit stumped. I looked around and some people suggested I set LayoutParams in addView, but why would this method work in onCreate, but not afterwards?
Here's what's happening visually(The first three rows are added from a loop in onCreate(), the two second ones are added by pressing "Add +"). As you can see the second spinner isn't showing up, sometimes both aren't showing up. I also tried calling invalidate and requestLayout to no avail.
I had looked into the invalidate method, here's where it is located currently :
public abstract class EditableForm extends RelativeLayout implements ObservableInt
{
private class OnAddClicked implements OnClickListener
{
#Override
public void onClick(View v)
{
onAddClicked(v);
EditableForm.this.invalidate();
mFormLayout.invalidate();
}
}
}
Which calls(In a subclass of EditableGrid) :
#Override
protected void onAddClicked(View clickedView)
{
addTwinSpinnerRow();
notifyObservers(new ObservableData(EDITABLE_ADD_GRID_CLICKED, null));
}
protected void addTwinSpinnerRow()
{
Locale.MapKey v1 = Locale.getInstance().getMap(mTSP.getFirstSpinnerRes()).get(0).getMapId();
Locale.MapKey v2 = Locale.getInstance().getMap(mTSP.getSecondSpinnerRes()).get(0).getMapId();
addTwinSpinnerRow(v1, v2);
}
Have you tried calling the Invalidate method of the container view rather than the added view?
Most likely the views you are adding are there, they just need to be drawn which is suggested by your keyboard hide/show difference. Does rotating the device also cause them to appear? If so, this again suggests that you need to redraw your custom layout.
When it's necessary to execute invalidate() on a View?
Hi I am developing android application in which I am using grid view. I want to updated grid item dynamically.My grid item contains one title text. I tried to do it like this but it is not working for me.
((Activity)context).runOnUiThread(new Runnable()
{
public void run()
{
Debug.print("this is update progress inside thread ...");
owner.setText("Uploading...");
invalidate();
requestLayout();
}
});
So in above code its printing debug statement. But not updating my owner text which is inside grid item.
I tried this also...
Handler handler = new Handler() {
#Override
public void handleMessage(Message msg) {
owner.setText("Uploading...");
}
};
handler.sendEmptyMessage(0);
Try to refresh your adapter which you used to load the grid item.
Either you could use invalidateViews() method or adapter.notifyDataSetChanged()
This will help you to resolve your issue.
Happy coding..
So in above code its printing debug statement. But not updating my
owner text which is inside grid item.
I think it's textview does not reference to your item in grid adapter. You can check it by set tag when init and getTag() inside runonUIThread method.
Let check this textview is local or global variable. If global, it's only reference to the last item - then check the last item change?
OK if it's not. Let post full ur code.
runOnUiThread(new Runnable() {
#Override
public void run() {
Debug.print("Updating UI ...");
owner.setText("Uploading ...");
invalidate();
requestLayout();
}
});
Check if you have any Thread.sleep() in your code that might be blocking the UI.
I've tried a lot of different ways, most of the suggestions found here, but none of them seems to work. What I'm trying to achieve is at chat area below my game area, a SurfaceView. It is supposed to scroll upwards as new lines are added to the textview.
At first, it looks like a really simple task, but having tried all kinds of suggestions, like a TextView in a ScrollView, like a TextView in a TableRow in a TableLayout in a ScrollView, and so on...I've still not made it happen. Of course this must be something easily achieved in Android, right??
The task is to display like 6 lines of text in the bottom of the screen, and as a new message is added last it should scroll the rest upwards, like a terminal window. The important thing is that it should add the latest message after the other and, when reached the bottom line, scroll the text upwards and add the new line(s) at the end.
Any kind of help or suggestions would be highly appreciated!!
I needed the same behavior in one of my apps and I achieved in just with one command:
view.setGravity(Gravity.BOTTOM);
Or, analogously, setting this attribute in your layout:
android:gravity="bottom"
Then simply add your lines using:
your_text_view.append(newLine);
Suppose, you declared your ScrollView as follows...
private ScrollView mScrollView;
you initialized it as...
mScrollView = (ScrollView) findViewById(R.id.scroll_view_chat_window);
Now, create a method to perform scroll down when you call the method. Inside the method implement a thread which will do the scroll down independently. And call the method after every chat message update thats will do the auto-srcoll functionality.
private void scrollDown() {
mScrollView.post(new Runnable() {
#Override
public void run() {
mScrollView.smoothScrollTo(mScrollView.getScrollY(), mScrollView.getScrollY()
+ mScrollView.getHeight());
}
});
}
I've achieved this (crudely!) by maintaining my own list, deleting the lowest element then adding at the end each time. Here i've just got a 3 line window:
public class MessageWindow {
private ArrayList <String> msgs;
private Activity parentActivity;
public MessageWindow(Activity act, int allMsgsMax) {
this.parentActivity = act;
msgs = new ArrayList <String> ();
// create empty list elements for initial display
for (int i = 0; i < allMsgsMax; i++){
msgs.add("");
}
}
//
public void put (String msg){
msgs.remove(0);
msgs.add(msg);
// get a handle to the textview 'messages', a 3-line box
TextView t2v = (TextView) parentActivity.findViewById(R.id.messages);
// crappy but you get the idea:
t2v.setText(msgs.get(0) + "\n" + msgs.get(1) + "\n" + msgs.get(2) );
}
then in the activity:
protected MessageWindow messageWindow;
// setup splash screen
messageWindow = new MessageWindow(this, 3);
// write some stuff - row1 will disappear off the top of the box
messageWindow.put ("row1")
messageWindow.put ("row2")
messageWindow.put ("row3")
messageWindow.put ("row4")
I have created a bunch of ImageButtons programmatically while in a for loop. They have worked fine as the data displayed in a HorizontalScrollView. Now I need each one to go dim or bright when clicked. First click will setAlpha(45); second click will setAlpha(255);.
I don't think I fully understand how the Views and onClickListener works yet. It seems the onClick function examples I find take a View. How would that function know which button is clicked? Perhaps there is an easier way to do what I want?
Here are the ImageButtons.
TableRow tr0 = new TableRow(this);
tr0.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
for(int but=0; but<ClueList.size(); but++){
ImageButton clueBut = new ImageButton(this);
clueBut.setBackgroundResource(0);
clueBut.setImageBitmap(ClueList.get(but).btmp);
//clueBut.setOnClickListener(this);
tr0.addView(clueBut);
}
Is there something I need to do to make the buttons identifiable? And how would that pass in through into the onClick function to be used?
-: Added Information :-
I am starting to wonder if the problem isn't with the buttons, but with the way I built the screen. More information added.
The Game activity is the main game, which uses the PuzzleView for the upper part of the screen holding the game grid. The lower part is where the ImageButtons are and I built them in place in the Game class.
public class Game extends Activity{
//various variables and stuff
private PuzzleView puzzleView; // The PuzzleView is from another .java file
// public class PuzzleView extends View
#Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
LinearLayout mainPanel = new LinearLayout(this);
mainPanel.setOrientation(LinearLayout.VERTICLE);
puzzleView = new PuzzleView(this);
mainPanel.addView(puzzleView);
HorizontalScrollView bottom = new HorizontalScrollView(this);
mainPanel.addView(bottom);
TableLayout clues = new TableLayout(this);
bottom.addView(clues);
TableRow tr0 = new TableRow(this);
for(int but=0; but<ClueList.size(); but++){
ImageButton clueBut = new ImageButton(this);
clueBut.setImageBitmap(ClueList.get(but).btmp);
tr0.addView(clueBut);
}
When I try to add the ClickListener(this) I get errors about this not being able to be a Game. I have similar problems in the onClick(View v) function referencing the View. Are these problems because I am building the buttons in the Game Activity instead of a View class?
Thanks
When you set up an OnClickListener and implement the onClick(View v) callback, it's the Dalvik VM the one that will call that method each time the View is clicked, and it will pass the View instance as a parameter. Thus, the code you write inside that method will be applied only to the View that received the click and not to any other View. Add something like this to your loop:
clueBut.setOnClickListener(new OnClickListener() {
public void onClick (View v) {
if (v.getAlpha() == 1f)
v.setAlpha(0.2f);
else
v.setAlpha(1f);
}
});
In the onClick event:
public void onClick(View currentView)
{
Button currentButton = (Button)CurrentView;
//Do whatever you need with that button here.
}
To identify each view uniquely use the property
View. setId(int)
In your case the code would look something like this
for(int but=0; but<ClueList.size(); but++){
ImageButton clueBut = new ImageButton(this);
clueBut.setBackgroundResource(0);
clueBut.setImageBitmap(ClueList.get(but).btmp);
clueBut.setId(but);
//clueBut.setOnClickListener(this);
tr0.addView(clueBut);
}
Inside the onclick listener match the id of the view using findViewByID()