Android redraw view example. How do i get the android layout .

Android redraw view example Then set RefreshListener like. Nov 29, 2013 · I'm trying to create a gridview that gives the possibility to the user to create a new child clicking on the last item on the gridview. Dec 7, 2024 · Calling the Android framework from Compose. After setting the image, I then call postinvalidate(). notifyDataSetChanged(); it did not work. . getList(); //array Jun 27, 2024 · A well-designed custom view is much like any other well-designed class. I now have a View that is added programically after the onCreate (Depending on some other variables). I have a fragment that inflates an xml layout. Create custom Jun 16, 2014 · I have 3 ImageViews. To learn more about system resources, see Resources in Compose. The text to be drawn is set using a global variable. getBackStackEntryAt(fragMgr. :) Here is the java code: packag Aug 19, 2012 · It gives you better control when using an MVC model where there's a dataset tied to a View. There are two methods for implementing view update in android. For example, it's hosted on Android View classes, like Activity or Fragment, and might use Android framework classes like the Context, system resources, Service, or BroadcastReceiver. view. Override View methods such as onDraw() to define the view's shape and basic appearance. In fact after the user c Android Studio project: CustomFanControllerSettings. This is achieved through a voting mechanism where each View votes based on its frame rate attribute, which can be a category or a specific rate. restore, etc Aug 30, 2013 · If the view is visible, onDraw(android. kt class GraphView(context: Context, attributeSet: AttributeSet): View(context, attributeSet) { GraphView. setAdapter(null) and then recyclerView. There is a fundamental design flaw in your code: the position of player is modified during the execution of the onDraw: you will be unable to control it. 2/ Custom View: draw it yourself using the canvas and math. MIRROR constant defines that the image is mirrored and Shader. i("Fav ", "onRefresh called from SwipeRefreshLayout"); // This method performs the actual data-refresh operation. Example. commit(); Jun 3, 2015 · This does not work for me. Preferences are defined in XML file - nothing funky just some categories and preferences nested within <PreferenceScreen/> Do I need to explicitly redraw the view? Jan 26, 2022 · Hello, I have a tile database but it lacks zooms (it is to save space). ListActivity. VISIBLE) call recyclerView. Since it is necessary to redraw, you must first inherit the View class. I working on messaging platform like whatsup. Oct 31, 2013 · First, your adapter. To call from a non-UI thread, call postInvalidate(). The view will be redrawn but the size will not change. Again, please let me know if this is unsafe or a bad practice and if possible a working alternative. These preferences are collected and combined to determine a final frame rate for each frame. You need to reload it. It also takes care of drawing the View background for you. So you could have a class that extends BaseAdapter. Compose operates within the Android framework classes. When I click on the button I want to hide a view (another button) that is loaded in the FrameLayout. ViewHolder> { private ArrayList<StatusBarNotification> myList; Context ctx; public class ViewHolder extends RecyclerView. But where can I put the Nov 11, 2021 · I am using DiffUtil with ListAdapter in Android Kotlin. setVisibility(View. I want to update the view if any data change on the server side, so it will reflect in the app. graphics. view. 1. Also note that the method notifyDataSetChanged() has to be called on UI thread. One is invalidate and the other is postInvalidate. GONE) and then recyclerView. Call `invalidate()` on a View object to request a redraw of the view. Isn't my case. CLAMP constant defines that the edge corners should be used to fill the extra space, the Shader. SwipeRefreshLayout class contains a listener called OnRefreshListener. attach(frg); ft. You could instead use an event-driven approach and implement a pattern like an Event Bus, to which consumers can publish and subscribe. ViewHolder { public ImageView appSmallIcon; public ViewHolder(View v) { super(v); appSmallIcon = // . 0" encoding="utf-8" Aug 3, 2012 · Yes, that was the plan B which I was going to tell you if you say me that the array adapter doesn't show the changes. In certain cases, the user has the ability to add items to one of the expandable lists. I am responding to this topic a long time after but because I have faced the same problem and I finally found the solution to the problem. That's what I needed to do, so gave an up-vote. This implementation also handles edge cases such as manufacture specific issues as well as starting/stopping the thread to save cpu time. These Material Design UI Patterns are seen in applications like Gmail, Youtube, Facebook, Instagram, etc. Adapter<MyListAdapter. android custom view redraw. Use the `notifyDataSetChanged()` method to refresh adapter-based views such as ListView and RecyclerView. I subclassed View to get an View on which the user can "draw" with his fingers. However, these views won't necessarily already have the correct images loaded into them, they are views that were previously being used for displaying different cells in the grid at different positions. I have a problem after a member posts a new comment the (recyclerView ) is not updated in real time. 12. Update the data binding in your layout using LiveData or ViewModel classes from the Android Architecture Components. The most important step in drawing a custom view is to … Jun 14, 2016 · This is how it looks at first: This is the dialog fragment that pops when "edit" is pressed and I want The change to be seen in the activity after the dialog fragment is dismissed. Aug 7, 2024 · In place of ListView, we use RecyclerView. Jun 27, 2024 · The most important part of a custom view is its appearance. I have a problem redrawing the view. Mar 20, 2024 · Custom views can be created in two ways: 1-) Inherite from android framework components (Button, FrameLayout etc. When I click on the button of the row of listview, a button will be created in the main. Whenever OnRefresh () method is called ArrayList data gets shuffled. In place of ListView, we use RecyclerView. ) 2-) Let’s consider a scenario where we have an avatar view composed of an Today we will learn how to redraw View! The so-called redrawing is to redraw its appearance (style). This works well for 90% items. Use invalidate() to force a draw or redraw of the view. beginTransaction(); ft. Can someone let me know the relevant APIs to dynamically update a TextView (or entire screen )? For example: I have a search application and I need to show the Apr 20, 2013 · Now I meet some problems with the redraw of the view. – Opiatefuchs Commented Sep 23, 2015 at 10:53 Sep 7, 2015 · In my app there's 2 tabs (Android Design Support Library) this is the Fragment with ViewPagerAdapter: public class ListaCanali extends Fragment { public static TabLayout tabLayout; public static. I have created a class RoundIcon which extends View and the class contains setIconImage() method: public void setIconImage(int imageFromResources) { iconImage = BitmapFactory. I think you want to refresh the fragment contents upon db update. Summary. But how about the SurfaceView ? It seems that postInvalidate() can be used to call its redraw. Oct 3, 2014 · We set the activity_main. I have selected one of x pages that are available to scroll through in ViewPager. notifyItemRangeChanged(0, adapter. View, I will override the onDraw() method, put all my graphic login inside this method . INVISIBLE. android redraw layout programmatically. In this example, we would store data of string type into the ArrayList which is used for populating the ListView. TileMode. getItemCount()); Share May 13, 2015 · The issue is in your getView() function. So, I firstly get the current fragment (that's the latest one in backstack ): BackStackEntry latestEntry=fragMgr. save, canvas. Everything works as it should and it draws part of a circle. ) and you didn't know whether this view will be placed inside other View that can intercept touch events or the view structure is even more difficult. When I change params of one view(for example re scale image or rotate) this causes to redraw whole Layout. What you need to do, is to create a private Pie property in your activity or fragment class like this : Jun 4, 2019 · GraphView. kt Aug 11, 2012 · AFAIK, a View's onDraw() is called when: The view is initially drawn; Whenever invalidate() is called on the view; Invalidate can be called by you or the system whenever needed. Aug 9, 2017 · How to refresh current Activity 1 time after load? My code refresh the activity, but in Loop. Here is a picture: I want to connect 2nd & 3rd ImageViews with new Path line and change the first line color (for example to Green) when i clicking my button. GONE will remove the View from the screen, and the space occupied by the View is released to other Views on screen. I am calling the data from the server in the onResume method. OnTouchListener. Feb 22, 2015 · For example, if you only need to refresh, or in other words, you want each view to be rebinded, just do this: adapter. Oct 31, 2024 · Note: The framework doesn't draw View objects that aren't in a valid region. This class binds your data to the View and this class also has a method: notifyDataSetChanged() which is what should solve your problem. Jul 18, 2016 · How to refresh view in android. int vWidth = view. One way is that I create a new GraphView instance in the loop which should be final but I don't want to redraw all my chart every time because every time it draw it first it move to right for a second and then expand and place in the proper position. If so, detach the fragment and reattach it // Reload current fragment Fragment frg = null; frg = getSupportFragmentManager(). It just needs to extend View from the Android Feb 22, 2024 · Now that you have a well-designed view that responds to gestures and transitions between states, ensure that the view runs fast. invalidate()); or. This is the following code I'm using to update the spinner. Call `invalidate ()` on a View object to request a redraw of the view. A neat trick if you want to redraw only one view from your adapter is to call getView manually for it if its position is visible - i. This makes your code more declarative, and thus readable. For a normal android. When i press send button ı must update View. Story: Whenever user clicks on item, it shows AlertDialog. . At some point during the program's execution, I want to change the global variable, and have the MyView redraw itself to update the text. 6. To properly draw your custom view, find out what size it is. setAdapter(adapter). For example, a lot of Views change how they look onTouch, like an EditText getting an outline and cursor, or a button being in the pressed state. After I get a new List of products, I tried to: Update the ArrayList from the fragment where recyclerView is created, set new data to adapter, and then call adapter. I tried fragment. May 8, 2013 · I have a class that extends View and have the onDraw method implemented in my xml file I have a FrameLayout with my view and a RelativeLayout with a button &lt;?xml version="1. My requirement is to update the text size on all my views inside my fragment when my Activity is resumed. decodeResource( call recyclerView. You should implement the behavior as follows. setOnRefreshListener( new SwipeRefreshLayout. I am saving Sep 3, 2015 · Performing a "refresh" to keep your fragment state up to date unnecessarily destroys and recreates the view when all you need to do is update your adapter data. If you want to keep the space, you can use View. Enable this behavior by adding the widget to your layout file as the parent of a ListView or GridView and implementing the refresh behavior that is invoked when the user swipes. Canvas) will be called at some point in the future. How do i get the android layout May 26, 2011 · This code for If you want first create the view and after that refreshing page at specified time span then use following code. Is there a way to make the redraw happen immediately? You must do this step every time the method is called, because the size of the view can change (for example, when the device is rotated). Now the View is NOT removed, instead, it hides the View and display blank space. Also I have simple button. activity_main); In these lines, we find our SurfaceView from our main layout and we get a holder, an abstract interface to someone holding a display surface. rawQuery( "SELECT * FROM ssnt WHERE mid = 1000" ); //optional, initial query adapter. Aug 14, 2014 · Stack Overflow for Teams Where developers & technologists share private knowledge with coworkers; Advertising & Talent Reach devs & technologists worldwide about your product, service or employer brand User interactions: The user has performed actions that should update the view. The Jan 15, 2012 · View. I think that the best choice for you is using SwipeRefreshLayout View in your layout. Feb 10, 2025 · The swipe-to-refresh user interface pattern is implemented entirely within the SwipeRefreshLayout widget, which detects the vertical swipe, displays a distinctive progress bar, and triggers callback methods in your app. the place for the view is just empty, but taken. I am not sure this could be refreshed directly or if I need to close it first and re-instatiate it? Jun 20, 2012 · Invalidate, invalidateviews, notifyDatasetChanged, nothin worked for me! To just update the listview (with cursoradapter) I just do: cur = db. You should post the complete code, there's no way to know if the array you're passing is always the same reference or not. xml layout and we initialize our main layout by:. In this example, we would store data of string type into the ArrayList which is used for populating the Aug 7, 2013 · So when you want to change the data or invalidate the view that you need, you can call the findViewWithTag() method on the ViewPager to retrieve the previously instantiated view and modify/use it as you want without having to delete/create a new view each time you want to update some value. I implemented the Interface View. When ı send message ı must update the screen because ı am getting data in db. In my case I was invalidating a container (a ConstraintLayout) but the view inside it didn't get redrawn until I called postInvalidate() (from a service thread) directly on the view. Time-based updates: Certain views may need to refresh periodically. Th Sep 25, 2009 · While scrolling, the whole screen get all messed up, again it looks like view is redrawn (when scrolled) without erasing the background first. Jan 3, 2011 · We should first know what is Pull to refresh layout in android . This example describes how to create a SurfaceView with a dedicated drawing thread. It will result in onDraw being called eventually (soon, but not immediately). Below I include the XML code for the drawer. View invalidate(int, int, int, int) part of a canvas, but onRedraw() the entire canvas? 0 Android Design: onDraw() not called after invalidate() Sep 18, 2021 · Here is my codes for custom view class: public class myView extends View {private Path path = new Path(); private Paint paint = new Paint(); //Constructor public myView(Context context, @Nullable Jul 12, 2015 · I am trying to figure out what is the issue with updating RecyclerView's Adapter. User can type some text by clicking ok button. My code is: finish();startActivity(getIntent()); Nov 22, 2011 · I need to update a custom dialog content whenever that dialog is ready to be drawin. getWidth(); int vHeight = view. My question is basically the same as How to force a view to redraw immediately before the next line of code is executed , but unlike this question I don't need to change background I am quite new to Android development. Feb 6, 2025 · In order to use this behaviour, we need to use the SwipeRefreshLayout widget as the parent of a ListView or GridView. This site have some examples, but most is after click button. 1st and 2nd connected with red line. This must be called from a UI thread. I googled but ı can not exact Dec 11, 2014 · You don't really can get the control on when the onDraw will be called: when a view is invalidate then the onDraw will be called at some point in future. When onResume called every item whole data is redrawing the view. But where can I put the Sep 22, 2014 · I can't recognise what is it's problem. requestLayout() I'm trying to refresh specific item in RecyclerView. How can I trigger within the onTouch method the redraw of the View? Do I need to implement a Thread / Runnable? I thought that invalidate() triggers the redraw, but this doesn't work. The Shader. getName(); Fragment fragment=fragMgr Aug 7, 2024 · Swipe-to-Refresh ListView is very much similar to Swipe-to-Refresh RecyclerView. You can force a View to draw by calling invalidate(). You may find notifyDataSetChanged example and customListView helpful. Any suggestions that I can understand would be great. Dec 13, 2012 · Calling invalidate() is done when you want to schedule a redraw of the view. The download is performed in a thread and in that same thread I also set an image view with the newly downloaded image. let us take an example, we have base View Group Component(RelativeLayout) which holds its all children. When they do so however, I cannot get the list to ref In this tutorial, we shall learn how to Refresh ListView using a Kotlin Android Application. Mar 28, 2014 · Basically I have a drawer with a button in it. Solutions. To refresh the ListView in Android, call notifyDataSetChanged() method on the Adapter that has been set with the ListView. getHeight(); int halfWidth = vWidth / 2; int halfHeight = vHeight / 2; Add an if-else statement for (mOffset == OFFSET). An example of when a custom view would call it is when a text or background color property has changed. If attached to a parent, it will be removed. notifyDataSetChanged() right before setListAdapter(adapter); in the onCreate() method is useless because the list isn't aware of the data unless you call setListAdapter(). Add removeSelf to directly call on a view. But id doesn't update! I tried using "invalidate()" and "postInvalidate()" but they doesn't work! Here is the code of RadarView: `public class RadarView extends View Redraw Canvas by calling invalidate method Description. Main Activity Java code Extend by device; Build apps that give your users seamless experiences from phones to tablets, watches, headsets, and more. Custom drawing can be easy or complex according to your application&#39;s needs. e. Here's tutorial that demonstrate about how to implement android pull to refresh. It allows the user to refresh the application manually. I hope this helps. First, create a new android project, we define a class, and inherit View, the class name is: DrawView: public class DrawView extends View {public DrawView Jun 27, 2024 · Views are redrawn frequently, and many drawing objects require expensive initialization. kt does not need to be fancy. xml, I am having the onclicklistener of the button in custom listView adapter. findFragmentByTag("Your_Fragment_TAG"); final FragmentTransaction ft = getSupportFragmentManager(). Just to be sure that we are on same page. This lesson covers some of the most common operations. Jul 20, 2010 · I've been trying to update my spinner in android dynamically but nothing I try has been working. I want to prevent redrawing whole layout and Dec 4, 2014 · android. GridView reuses views by passing them to getView() in convertView. Nov 30, 2016 · I have GroupView which contains 4 ImageViews. I tried many examples and source code from the internet, but it still didn't work on my PC like the invalidate func, canvas. Ok. It encapsulates a specific set of functionality with an easy-to-use interface, it uses CPU and memory efficiently, and so forth. I would like to display the parent zoom instead of the front zoom which is in the view. So, a "GONE" view cannot come back. The former is used in the UI thread itself, while the latter is used in non-UI threads. In my android app, I download an image from the cloud. In addition to being a well-designed class, though… Jun 27, 2012 · Can anyone help me on how to redraw the canvas. Example here I have a zoom 15 and a z Android UI How to - Redraw Canvas by calling invalidate method. OnRefreshListener() { @Override public void onRefresh() { Log. typeList = dbAdapter. And call the invalidate() method when I want it redraw. Dec 14, 2016 · In Android development, we often come across requirements relating to refreshing a View periodically. extends View. When I refresh, it appears that the old data draws on top of the new data, until a scroll event happens. Jan 5, 2013 · runOnUiThread(() -> view. setContentView(R. For example, after a user login occurs that needs to expose more info or options within each view of the listView. So for now I'll be using onCreate(null) to refresh my view when I update data. From menu I invoke action that somehow process data in underlying db and change it. Oct 22, 2010 · Kotlin Extension Solution. public Dialog Mar 5, 2024 · so there are two different ways to do this: 1/Combine different Views: such as TextView, ImageView, and Drawable resources. I am quite new to Android development. getView(). Back to Canvas ↑; The following code shows how to Redraw Canvas by calling invalidate method. invalidate() call recyclerView. So if something changes and it needs to be reflected on screen, you need to call invalidate(). However the image does not immediately show up. But my question is how do i redraw it later on ? Use the `notifyDataSetChanged ()` method to refresh adapter-based views such as ListView and RecyclerView. The following code shows how to Redraw Canvas by calling invalidate method. If the underlying data changes, it's probably a better idea to use notifyDataSetChanged(). I want to show this text in this item and show invisible ImageView - declared in XML and adapter ViewHolder- Jun 11, 2014 · If you want to create custom view in which have to be your custom drawings for different touch states (pressed, selected, focused etc. Feb 5, 2011 · My ListView is using an extension of BaseAdapter, I can not get it to refresh properly. Oct 26, 2024 · In Android development, when you add a new view to a ViewGroup (such as a LinearLayout), you need to ensure that the layout and visual representation of the UI are updated to reflect this change Two options: either hold onto the reference for the ArrayList that you passed into the constructor so you can modify the actual list data later (since the list isn't copied, modifying the data outside the Adapter still updates the pointer the Adapter is referencing), or rewrite the Adapter to allow the list to be reset to another object. Redraw View Android. Mar 27, 2013 · Most of the previous answers do a good job explaining how, why, and when to use onResume() but I would like to add something about re-creating your Activity. However, for built-in widgets you rarely, if ever, need to call it yourself. Sep 9, 2012 · I create my own View (RadarView), extending View. I mean I just want to redraw chart every 7 second I think that the best choice for you is using SwipeRefreshLayout View in your layout. To avoid a UI that feels sluggish or stutters during playback, ensure that animations consistently run at 60 frames per second… Jul 24, 2013 · notifyDataSetChanged() will redraw all views in your adapter. invalidate(); After this, I would like to refresh my currently displayed fragment's view to display with new locale settings. I have looked EVERYWHERE and my little brain just can't understand a better way to refresh an activity. when you swipe screen from top to bottom it will do some action based on setOnRefreshListener. layout. This project shows you how to use Android's native webview wrapper to load site url, how to add and dismiss progressBar, and how to utilize the Swipe to refresh feature of Android's webView - GitHub - Luckae/Android-WebView-Example: This project shows you how to use Android's native webview wrapper to load site url, how to add and dismiss progressBar, and how to utilize the Swipe to refresh May 1, 2013 · I have a ListView. REPEAT defines that the image will be repeated. I want to know if I want to restart the activity at the end of exectuion of an other what method is executed onCreate() or onResume() GONE means only, that the view is not taking any space in the layout, INVISBLE means, the view takes space eg. postInvalidate(); Also note that redrawing a container might not redraw all of its views. – I have created a custom View (let's call it MyView) which basically just draws some text on itself using the canvas. For example, a timer which counts down every second or a counter which counts up every second. Jun 27, 2020 · When Activity brings to focus, the Android Framework request activity to provide the root node of its hierarchy(Top View Element in Layout file). Jan 29, 2025 · In Android's View system, each View in the UI hierarchy can express its preferred frame rate. Aug 23, 2014 · However, if I remove the character in the same method that I create and share the image, the app crashes because it didn't get a chance to redraw the view first. (here mention refreshing rate is 20 seconds) It Works Fine and Automatic refresh in every 20 seconds. changeCursor(cur); // or swapCursor(), cur is the initial and the only cursor Mar 28, 2017 · public class MyListAdapter extends RecyclerView. Only 90% of items will get the new style, but some items will have the old style Feb 12, 2010 · This is the correct answer if one only needs to REDRAW the view. Creating drawing objects within your onDraw() method significantly reduces performance and can make your UI sluggish. Jun 27, 2016 · If the area which is filled is larger than the Shaders you can define via the Shader tile mode how the rest should be filled. To create a custom view of any size and shape, add a new class that extends View. The Android framework draws the layout in a two-pass process: a measure pass and a layout pass. we can call pull to refresh in android as swipe-to-refresh. mySwipeRefreshLayout. Please refer to Pull to Refresh with RecyclerView in Android with Example. when you have multiple rows and each one updates independently from the others. detach(frg); ft. Depending on Dec 22, 2015 · I have an Activity that contains an ExpandableListView. May 18, 2012 · Generally, invalidate() means 'redraw on screen' and results to a call of the view's onDraw() method. getBackStackEntryCount()-1); String str=latestEntry. Apr 24, 2020 · I am working on developing an application that contains (recyclerView ) display member responses. doons xyst mgibtrs hylso zcbr sgjpda irmedlo fwi tmrhi dht vzzetq zmoyk ckyct smyqw dqdnfrc