Android :: List View Methods Invalidate Vs Invalidate Views?
Dec 23, 2009What's the functional difference between these list view methods: invalidate() and invalidate Views() ? Which one is faster to refresh a list view?
View 3 RepliesWhat's the functional difference between these list view methods: invalidate() and invalidate Views() ? Which one is faster to refresh a list view?
View 3 RepliesI have an List Activity with a Base Adapter where the contents have changed (example - the rows are reordered). I have tried invalidate.
Code...
The green plane is shown on the golden-brown surface but when I press a key nothing happens. I want eventually be able to move the plane pressing 4 different keys + another one for shooting but that's easy if I can just get the thing moving in the first place. When I press a key in the emulator, nothing happens at all.
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What is the use of Invalidate() in android?...
View 4 Replies View RelatedI have a ListView, its rows each have an image downloaded from the net in a separate thread. When the image is done downloading, I notify my main thread, and need to invalidate the corresponding row if it's on screen.
View 4 Replies View RelatedI am new to Android. Can someone show to me how do I force invalidate a portion of an item in listview? I have listview row item that contains textview and image view. I only want to invalidate text in the textview of a particular item in the listview.
View 3 Replies View Relateddoes rooting invalidate insurance on orange care?
View 5 Replies View Relatedwhat parameters do I pass to this function? invalidate(left, top, right, bottom) for use with google map on android ?
View 1 Replies View RelatedI am new to Android development, just reading docs and trying the APIs. I am quit confused how ImageView managed to draw just a part of its content after an invalidate(Rect) invocation.
I've checked ImageView.java, found no other drawing method except onDraw(Canvas), but onDraw(Canvas) only cut the drawable only if it is beyound the view's visible boundary. I also read the implementation of View.invalidate(Rect), I think the key of this function is calling to mParent.invalidateChild(this, r);
However, I think the parent view doesn't know how to draw the child in the given Rect, it finally has to call some method of it child to paint out. Has anybody investigated this part of codes? Would you please give me some guide?
I have a simple draw application on Canvas. User should be able to draw with a chosen color. On MotionEvent.ACTION_UP, invalidate() is called. Now it redraws previously drawn lines with the current color ( Redrawing the entire drawing with the current color). I do not want to change the color of previously drawn lines. I am not sure what is missing. Can I make it redraw only newly drawn lines?
View 4 Replies View RelatedI have table with 3 columns which is binded to an XML document with three text views.
CODE:........
Depending on the value store in the third column, I want to change the text color in R.id.c. How should, I go about with this.
This is what I have so far :
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I have a simple ListView and on that ListView I have placed a number of custom defined Views. The CustomView has ImageView and two TextViews.
The CustomView also has a "stateful drawable" as background, so that the background image (a 9-patch) changes if you press the Row in the ListView. When pressing the Row, the background image changes to a Red-ish thing.
The problem is that when the background changes from the default greyish, all the Views in the CustomView (ImageView and TextViews) still have their greyish background and thus creates very ugly greay boxes on top of the now redish background.
What is the best way to solve that problem? I hoped that such things were handled automatically (as it is done in for example .NET), but I was wrong it seems.
I am on Android 2.1 and I have one multi column Custom listview Using BaseAdapter with an editable edittext at the end of the listview. If the data in the listview do not contain the data of user choice then user should be able to enter data. If the data is already there in the list user will be able to select the data using custom selector. If a selection is made in the list view and user wanted to enter data in the text field at the bottom after selection then the marker in the list view should be unselected. I tried to use onclick() method on edit text using click listener. First time when it is clicked, edit text is getting focus and onclick() method is not fired. And when it is clicked second time, onclick() method is fired and notifyDataSetChanged() method is called. I tried to call the notifyDataSetChanged() method from the Focus Listener, list view selection is gone in my first attempt and edit text is not receiving any data input from the keyboard (frozen).
View 1 Replies View RelatedI'm trying to tackle a problem that seemingly many Android developers have, which is how to intersperse lists with non-list data, in one big scrollable pane.The model I have in mind is the screen for an individual app in the Market. You have a big description, a list of a few lazily loaded comments, and then some individual items that do different things, like visit the developer's web page, call them, etc. And then in between them all, are nice section headers.Emulating this approach seems to be extremely hard. I've read enough SO answers and mailing list posts to know not to put a ListView inside of a ScrollView, but I want the same effect without using addHeader() and addFooter() with very complex header and footer views. I've tried using a LinearLayout that I stock with views myself, but I can't get the pleasant click effects that default list items have (the orange background, white for long-click, etc.).
View 2 Replies View RelatedI'm trying to display a list of all the Input Methods that are currently installed on the phone.Does anybody know how to accomplish this? I don't care how I have to do it, I just need to be able to produce a list of Input Methods as they appear in the phone's Language and Keyboards menu and then store the user's selection. I thought maybe I could just use the InputMethodManager to launch the standard Input Method selection menu and then see which one the user picked by looking at which IME is currently selected after the menu closes, but as far as I can tell there's no way to see which IME is currently selected in the system.
View 1 Replies View RelatedI'd like to show another List View 'B' after clicking a item of List View 'A'. I use onListItemClick event in Android 1.6 project.
View 6 Replies View RelatedIs it possible to have a horizontal list view with an vertical list view? I would like to horizontal list scroll within a vertical list scroll.
View 13 Replies View RelatedI know that Android provides some useful methods to be overridden in order to define a menu:
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I would like to have this menu shared by each Activity and ListActivity of my Android application. This is for having a standard menu in each (List) Activity that lets the user jump to every part of the application within a click.
Right now, the easiest way to achieve this is to copy-and-paste both methods in every (List) Activity of the application. I don't like this redundancy of code written.
Is sub-classing a reasonable choice? I've already seen that sub-classing one of my ListActivity does not work very well (threads that retrieve objects from a database are giving problems). Are there other ways to share a menu though Activities?
I am trying to set up a ViewFlipper that changes a SlidingDrawers content each time a button is pressed. So far every view I set up worked fine, but now I am trying to create a ListView (including single_choice_mode) within a child view of the ViewFlipper, but my attempt only let to a NullPointerException. As I only discovered ViewFlipper today, I am not yet familiar with it and may not have understood it completely. if someone could give me a hand and help me find out what I have done wrong, that would be great. Here is what I have done:
The code for the onClick event of the ImageButtons:
public void onClick(View v){
if (v == btnExposure){
mFlipper.setDisplayedChild(0); }
else if (v == btnProperties){
mFlipper.setDisplayedChild(1);}
else if (v == btnSpecialEffects){
mFlipper.setDisplayedChild(2);.............
I'm trying to create a multiple selection list where the selection is represented graphically rather than with checkboxes.My list has checkboxes, but I want them to serve a different purpose. I'm using a cursor to hold my data and created a custom view binder for the SimpleCursorAdapter. I did this for the checkboxes and general flexibility.So far I haven't even been able to show one line as being selected. I've enabled multiple selection on the list and denied the children of the list item focusability. I've tried manually changing background color with the position fed in through the list item click listener. But the wrong items get changed and they don't even change to the right color. I've enabled touch focusability with no improvement either.Ideally, I'd like the trackball highlight focus bar to appear in multiple places. But I don't think this is possible unless you use the drawable directly. But I don't know how to find or apply it. My next idea was to have a slim view bar that changes color. But I had the same problem with the wrong item being selected so I never finished trying to guess the index position to see if this would work. My most recent idea is to completely swap out the view for another one if it's selected. But I have no idea how to do this either. I'm thinking of using an array list to store the _id s of the items that need a different view to get around the wierd selection problem. I'm also thinking of passing in the ID field as my from and the selection view as the to for my adapter. Then I'd intercept it with my binder and change the view accordingly. But once again, I'm not sure how to do this successfuly.
View 7 Replies View RelatedI am trying to display the text from json in a list view.But my problem is that i cant figure out how to display them in list view. I also want to get only some of the text from url(for example, alerttext and date). Can anyone help me in declaring the list adapter and list view in order to display the data in the way i want.
View 1 Replies View RelatedI'm still trying to figure out how best to layer views on top of other views. I want to do something like the ZoomButtons on top of a custom view. I tried getting the ZoomButtonsController's parent and then adding views, but I didn't have enough control and they ended up on top of the buttons. I've gotten close by using a FrameLayout and some gravity on the top two views. But this has some interesting effects. Since this is contained with a tab, these two top views appear on top of all four of the tab pages. I want them on top of one of those pages only. Apparently, nested FrameLayouts don't mix well. What is the proper and expected way to do this? Here is more or less my complete layout....................
View 4 Replies View RelatedIs there a possibility to add a view or derivative (button, textview, imageview etc...) to another view without having to go through layouts?
I have a class called ScreenView, it derives from View (e.g. public class ScreenView extends View).
I wanted to display text into it, labels, images etc..
On an iPhone it's trivial, simply create my objects and use addSubview method ; you can embed any UI objects into another. Most UI toolkits work that way too.
Problem with layouts is that I haven't found an easy way to properly position a subview (say a text view) in a given location of the enclosing View. I want one to contain the other...
I was hoping I had missed something in the documentation (which is far from being intuitive that's for sure) and I could do something like myView.addView(subview). But it ain't so :)
As a side question, what is the closest to iPhone's UILabel in the Android world?
A UILabel can contain a text or a graphic. Right now I've been using TextView and ImageView but they aren't anywhere as flexible when it comes to layout as a UILabel
Edit: Making my View inherit from ViewGoup instead, let me add subview..
However, I want to draw in my view. I found that when ScreenView extends ViewGroup, the onDraw function is never called then.
Something like:
CODE:..........
Would paint in yellow my view if ScreenView extends View ; but not if it extends ViewGroup.
How do you draw directly in the view then?
By Default in the Listview,focus will come on the list item.Instead of that, can I get only the border to the list item?I can achieve this by using a transparent image as a list selector.Is there any other simplest way to achieve this requirement?
View 1 Replies View RelatedI need to be able to scroll through a list with (up to) 20K rows, backed by a cursor on a read-only db. Testing 20K rows on a G1, the query takes approx .02s regardless of table size, while binding the adapter to the list takes 4.5s. Note that this is before the view calls used in rendering. What makes the binding delay more troublesome is that it blocks the UI thread, and is incurred on every rotate. Combine these, and doing a rotate just after starting the bind results in a delay up to 9s.
I tried lazy loading with a base adapter, but that hits the same delay in the underlying cursor.getCount(), and the overall user experience isn't ideal. I also considered using an ArrayAdapter, adding synthesized objects from the cursor rows, but then I'd incur the overhead of creating up to 20K objects (not to mention the additional memory requirements).
The reason for me to do this, I have created these 2 views in the beginning of the app. SO they are always present. But in some cases where i want only 1 view(which is surfaceview) and if i dont need the 2nd view(i.e, videoview), i am still getting a black patch at the palce where i have defned a videoview. want to get rid of this. Can anyone please tell me if it is possible to disable views/surfaces corresponding to them? If so how can we do this?
View 2 Replies View RelatedI am trying to figure out how to add a child view to a parent view so I can use the MotionEvent.ACTION_MOVE feature to move from one child view to the next. Is this possible?
View 4 Replies View RelatedI've tried to add a TextView before a ListView in a LinearLayout. The result is that the ListView wont show at all. The same thing happens if I put the TextView after the ListView, but then I will only see the ListView. Is there a way to get a text view above the ListView without to much of a hassle?
View 10 Replies View RelatedIn my app i'm setting background to each child views in listview. So that listview default focus ( orange color ) is not focusing. Is there any way to set both ( listview focus & child view background)?
View 1 Replies View RelatedPlease advice how to set fixed heigh (in dip) for the child view of ListView component? I am using relative layout as root layout for the child view when I set backgoround image to relative layout it becomes very height (maybe because backgoround picture is large) and I want to set precisely the height in dp.
View 1 Replies View Related