Develop Reference

ListView (Inside CardView) visually bugs upon resizing. Gif inside

FIXED: I was incorrectly updating my ListView adapter. see: How to refresh Android listview?
I have been struggling with an incredibly weird bug for too long of a time, and I wonder if any of you have had similar problems.
A detailed explanation of the bug will be less clear than for me to just show you, so I have attached a gif that displays exactly what goes wrong below.
http://giphy.com/gifs/xT9DPGixQnDIEHlVU4
Question 5 is included to show you how things are supposed to wrong. Then, when the CardView and the ListView inside it resize because the amount of options changes at question 6, the following goes wrong:
- The colors of the listview items do not get updated according to their correctness. (should be either green or a light shade of red)
- The checked RadioButton weirdly gets unchecked, right before I click the button.
Note: this bug only appears once upon resizing of the Listview. Everything proceeds to work fine once a similar size optionlist is supplied at the next question
These actions take place upon the second click of the button, which calls the following code
/*
FOR EACH LISTITEM:
> Make button unclickable
> Animate background change according to correctness of answer
*/
for (int i = 0; i < currentQuestion.getOptionList().size(); i++) {
ListView optionList = (ListView) rootView.findViewById(R.id.optionList);
View item = (View) optionList.getChildAt(i);
item.findViewById(R.id.optionRadioButton).setClickable(false);
final LinearLayout llayout = (LinearLayout) item.findViewById(R.id.itemLinearLayout);
int colorTo = getResources().getColor(R.color.lightPrimary);
if (currentQuestion.getOptionList().get(i).equals(currentQuestion.getAnswer())) {
colorTo = getResources().getColor(R.color.correct);
}
int colorFrom = getResources().getColor(R.color.white);
ValueAnimator colorAnimation = backgroundColorAnimator(
colorFrom,
colorTo,
llayout,
i);
colorAnimation.start();
}
// Bottom part of list view is animated SEPERATELY.
// please note that THIS DOES GET UPDATED ACCORDINGLY.
int colorFrom = getResources().getColor(R.color.white);
int colorTo = getResources().getColor(R.color.lightPrimary);
// Also increments question correct counter (important
if (correctAnswerSelected) {
colorTo = getResources().getColor(R.color.correct);
currentExercise.questionCorrectlyAnswered();
}
ValueAnimator anim = backgroundColorAnimator(
colorFrom,
colorTo,
fabContainer,currentQuestion.getOptionList().size()+1);
anim.start();
My hypothesis: Somehow, upon resizing the CardView / RelativeLayout / ListView, the ListView gets reinitiated and I call a different version of it. I suspect this is the cause because the lower part of the CardView (a FAB within a FrameLayout) does change color accordingly.
Any and all help is appreciated, I am at a complete loss with this question
Thanks in advance.

Animating crossfade between 2 layouts

I'm trying to implement an animation which crossfades between 2 layout, with a layover between them. The first layout is the main layout, the second is a simple linear layout with textView and red background (your classic "Wrong!" screen if you will...). My goal is to animate a quick transition between the mainLayout and wrongLayout, have the program wait for a short period of time while displaying the wrongLayout and then automatically return to mainLayout. This turns out to be extremelly hard, I've tried using monitors, Thread.sleep() etc. but what I get is that the program waits before starting the animation and THEN performs it without any layover.
My code is as follows:
In the main method-
LinearLayout wrongLayout = (LinearLayout) findViewById(R.id.wrong_layout);
RelativeLayout mainLayout = (RelativeLayout) findViewById(R.id.main_layout);
int animationDuration = getResources().getInteger(
android.R.integer.config_longAnimTime);
crossfade(wrongLayout, mainLayout, animationDuration);
/* This is where I want it to wait for 1 second */
crossfade(mainLayout, wrongLayout, animationDuration);
and the crossfade method-
private void crossfade(View fadeInLayout, final View fadeOutLayout,
int animationDuration) {
// Set the content view to 0% opacity but visible, so that it is visible
// (but fully transparent) during the animation.
fadeInLayout.setAlpha(0f);
fadeInLayout.setVisibility(View.VISIBLE);
// Animate the content view to 100% opacity, and clear any animation
// listener set on the view.
fadeInLayout.animate()
.alpha(1f)
.setDuration(animationDuration)
.setListener(null);
// Animate the loading view to 0% opacity. After the animation ends,
// set its visibility to GONE as an optimization step (it won't
// participate in layout passes, etc.)
fadeOutLayout.animate()
.alpha(0f)
.setDuration(animationDuration)
.setListener(new AnimatorListenerAdapter() {
#Override
public void onAnimationEnd(Animator animation) {
fadeOutLayout.setVisibility(View.GONE);
}
});
}
Thanks a lot...

Ok, so I've found this post which deals with just about the same problem-
Why the Sleep executes first and than the code above it in android?
I've changed the appropriate execution function and now it seems to work properly, though I'm still puzzled by the fact that I cannot cause the code to stop at a designated location for a specific amount of time. Oh well...

Android - textviews are not visible when dynamically created

I am trying to make an app that lets the user store and saves contacts. It can save, but it has problems listing.
I have a for loop that runs through the database and prints a set of data for each contact (each row), an image (actually its a string because it passes the path) and a string. It prints them in a scrollview with a linear layout for each contact (each contact has a linear layout of its own, so that i can let one contact occupy a row each). The images come out, however, the textviews are nowhere to be found.
Using log.d(textview.getText()); it confirms that the textviews are created and take up space.
http://chesnutcase.heliohost.org/derpbox/itv1.png
Two "contacts" with names, not printed out. The space inbetween is presumbly by the textview.
http://chesnutcase.heliohost.org/derpbox/itv2.png
Another two "contacts", but without names. The dont have a space between each other. Or at least, a significantly smaller space.
Code:
DatabaseHandler db = new DatabaseHandler(this);
int a = (int) (long) db.countRows();
LinearLayout theLayout = (LinearLayout)findViewById(R.id.contactsList);
for(int i = 0;i<a;i++){
ImageButton image = new ImageButton(this);
int density=getResources().getDisplayMetrics().densityDpi;
LinearLayout.LayoutParams vp = new LinearLayout.LayoutParams(density,density, 0.5f);
image.setLayoutParams(vp);
image.setScaleType(ImageView.ScaleType.FIT_END);
int b = a - i;
try {
image.setImageBitmap(decodeUri(Uri.parse(db.getContactData("photo_path")[i])));
} catch (FileNotFoundException e) {
e.printStackTrace();
}
theLayout.addView(image);
TextView tv = new TextView(this);
tv.setText(db.getContactData("name")[i]);
Log.d("UserLog","name is " + db.getContactData("name")[i]);
Log.d("UserLog","textfield contains " + tv.getText());
LinearLayout.LayoutParams vp2 = new LinearLayout.LayoutParams(0,0,1f);
tv.setLayoutParams(vp2);
tv.setBackgroundColor(Color.RED);
theLayout.addView(tv);
}
Any solutions? Thanks in advance

Double check which orientation you've applied to the LinearLayout of your contacts list.
You are setting bad LayoutParams to your TextView. You're making your TextView 0px by 0px with a weight of 1.
LinearLayout.LayoutParams vp2 = new LinearLayout.LayoutParams(0,0,1f);
tv.setLayoutParams(vp2);
Try using one of the MATCH_PARENT or WRAP_CONTENT constants. They're listed here: http://developer.android.com/reference/android/view/ViewGroup.LayoutParams.html#MATCH_PARENT
If you want your TextView to take up the remaining width of the screen I would leave the weight as 1, the width as 0, but you need to set the height to a constant like WRAP_CONTENT.
You're also setting the size of your ImageView to the device screen density (which is a constant) instead of setting a scaling size based off your screen density.

You probably need to call requestLayout(); in order to update the current view layout.
theLayout.requestLayout();
Also it seems you are creating a view with 0 width and 0 height with that layout params:
LinearLayout.LayoutParams vp2 = new LinearLayout.LayoutParams(0,0,1f);

It is better to use ListView for such list.
You will need to write only one Adapter, that's represent logic for creating one row on list.

I would recommend using a CursorAdapter and a layout xml file, this way you can design it to look exactly how you want, and preview it. It is a lot easier than setting all those fiddly LayoutParams
If you have to create them dynamically you may find the text colour is the same as the background, try setting it to something visible like bright red for testing. If you still don't see the text it may be that it's visibility isn't set to View.VISIBLE finally the layout may not be the correct size, a handy tip for this is set the background to a suitably eye catching colour, even if there is no text you should see a shaded block.

No vertical scroll in browser

I'm developing a Vaadin application and am having extreme difficulty getting some aspects of the layout as I want. The major problem right now is that I can't seem to get a vertical scroll in my layout no matter how big the size of the content is or how small the browser window is..
I have read up on the subject, I know that the hLayout and the vLayout doesn't support scrollbars but the Panel do. I've tried in many different combinations to make it work but I've only managed to get a horizontal scrollbar to generate but never a vertical one.
Another problem is that I'm building the application inside an existing "template" provided by the company. This template contains a footer containing some copyright information. This footer doesn't seem to occupy any space in the browser window with regards to the content I'm adding, which causes when viewing on smaller screens the horizontal scrollbar to appear "underneath" the footer, non-accessible... I'll provide some of the code of how it looks now.
public class InventorySimCardTable extends M2MViewBase { //M2MViewBase extends VerticalLayout
private final SPanel mainContent = Cf.panel("");
private final SPanel tabPanel = Cf.panel("");
private final SVerticalLayout tabcontent = Cf.vLayout();
protected InventoryFilterPanel inventoryFilterPanel;
#Override
protected void initComponent() {
setSizeFull();
tabPanel.setSizeFull();
tabPanel.getContent().setSizeUndefined();
Table simCardTable = new Table();
simCardTable.setWidth("1898px");
simCardTable.setPageLength(15);
tableContainer.setSizeUndefined();
tableContainer.addComponent(simCardTable);
mainContent.setWidth("99%");
mainContent.setHeight("100%");
mainContent.setContent(tableContainer);
mainContent.setScrollable(true);
centeringlayout.setSizeFull();
centeringlayout.addComponent(mainContent);
centeringlayout.setComponentAlignment(mainContent, Alignment.MIDDLE_CENTER);
tabPanel.addComponent(centeringlayout);
addComponent(tabPanel);
}
}
I would love to know if anyone sees any obvious errors in my code. And if anyone knows what property I can set on the footer CSS to have it occupy space in the content view so that the horizontal scroll doesn't appear underneath it. Thank you!

What I did to solve this issue was to structure the code as follows. This will create a vertical and horizontal scroll bar for the Panel holding my filter component and the table. Hopefully this can help someone with a similar problem.
#Override
protected void initComponent() {
super.initComponent();
if(!tableCreated) {
createSimCardsTable();
tableCreated = true;
}
mainWindow = this.getWindow();
Panel basePanel = new Panel("");
basePanel.addComponent(inventoryFilterPanel);
AbstractComponent separatorLine = Cf.horizontalLine(); //Of no signficance
separatorLine.addStyleName("m2m-horizontal-line-list-separator");
separatorLine.setWidth("99%");
basePanel.addComponent(separatorLine);
basePanel.addComponent(simCardTable);
basePanel.setSizeFull();
basePanel.getContent().setSizeUndefined(); // <-- This is the important part
addComponent(basePanel);
setExpandRatio(basePanel, 1);
}

All Vaadin components have size undefined by default, so usually there is no need to call method setSizeUndefined(). Also there is no need to call setScrollable(true), because it enables only programmatic scrolling possibility.
When I was trying to make a sense of scrolling appearance I wrote a simple skeleton of layout. Try this out as a content of the main window:
import com.vaadin.ui.HorizontalSplitPanel;
import com.vaadin.ui.Label;
import com.vaadin.ui.Panel;
import com.vaadin.ui.VerticalLayout;
public class Skeleton extends VerticalLayout {
public Skeleton() {
setSizeFull();
addComponent(new Label("Header component"));
HorizontalSplitPanel splitPanel = new HorizontalSplitPanel();
Panel leftComponent = new Panel();
Panel rightComponent = new Panel();
splitPanel.setFirstComponent(leftComponent);
splitPanel.setSecondComponent(rightComponent);
for (int i = 0 ; i < 200 ; i ++) {
leftComponent.addComponent(new Label("left"));
rightComponent.addComponent(new Label("right"));
}
leftComponent.setSizeFull();
rightComponent.setSizeFull();
addComponent(splitPanel);
setExpandRatio(splitPanel, 1);
addComponent(new Label("Footer component"));
}
}
You should see scrollbars inside the nested panels. But if setSizeFull() is removed from Skeleton layout, then it is not limited in size (by default) and grows downwards - then only the scrollbar of the whole window appears.

Add this to your styles.css
.v-verticallayout > div {
overflow-y: auto ! important;
}

First of all try to make your panel scrollable by calling setScrollable(true) method, but this will not work if you set some custom layout with setSizeFull() as this panel new layout.
If you exactly know that you application will be opened in device with small screen resolution, you simple can set for your "primary"/"main" layout some fixed width and height, or add some CSS style with params like min-width: {some value} px, min-height: {some value} px.

Based on this post, I added vertical.setSizeUndefined(); and started seeing vertical scrollbars.
setMainWindow(new Window(title ));
vertical.setSizeFull();
vertical.setHeight("100%");
toolbar = createToolbar();
vertical.addComponent(toolbar);
vertical.setExpandRatio(toolbar, 0.03f);
Component tree = buildTree();
vertical.addComponent(tree);
vertical.setExpandRatio(tree, 0.97f);
vertical.setSizeUndefined();
getMainWindow().setContent(vertical);>

The only way I could fix this now (v6.8.14) is to specify the height in px values in stead of %

Use CustomLayout, always. It's faster, more efficient and by controlling html and css easily you can acieve a graphically consistent result

How to I fix the background image to line up? (Blackberry)

I used some code that I found from another question. I commented out the setPositionChild() part because I wasn't sure what values to put for positionY and positionX. When I run the app, the background image is on the top and the buttons that I add to the manager later are all pushed together at the bottom of the image.
Background bg = BackgroundFactory.createBitmapBackground(Bitmap.getBitmapResource("Background.JPG"));
Bitmap bmp = Bitmap.getBitmapResource("Background.JPG");
BitmapField imgField = new BitmapField(bmp);
// Create the field manager
VerticalFieldManager manager = new VerticalFieldManager()
{
// Overide the sublayout of the field manager to set the position of
// the image directly
/* protected void sublayout(int width, int height)
{
setPositionChild(imgField, positionX, positionY)
setExtent(width, height)
}*/
};
// Set the background of the field manager
manager.setBackground(bg);
// add the bitmap field to the field manager
manager.add(imgField);
// add the field manager to the screen
add(manager);

Please mention what you are trying to achieve here. What's your expected behavior? Looking at code, the child fields should be positioned as you have mentioned when you run app. Since you are adding BitmapField (imageField) to manager and then probably adding buttons(not shown in code, assuming you are adding it somewhere else in code) to the manager. So provide more details on what you want to achieve?