Android most efficient way to have many views - java

I have an app that will allow the user to drag many views onto a "canvas". The user can pan, rotate, flip, and scale these views. Each view will need to have a image on it. I was thinking of simply inflating imageviews and letting the user interact with those.
Is there a more efficient way to have up to 50 images on screen that can be interacted with?
If so, can you point me to some code examples?
EDIT:
I have noticed there are multiple ways to do this:
Some tutorials use a surfaceview and bitmaps and threads
Other tutorials use open gl
Other tutorials simply have views on views,
What route should I take?
Thanks

Check out this app:
https://market.android.com/details?id=com.sunshine.fingerpaint
By using a Horizontal Scroll View at the top of the application, you could inflate the 50 images you want and let the user interact with them.

Related

Android keep button or view in front of all activities within the app without using baseActivity

After a lot of time spent I can't find the solution. I want a button or any clickable view should stay visible for all activities and it should be only for one specific app not like chat heads. I am basically making a library so that's why I can't use base activity.I have attached the image as well for a better explanation. How can I achieve this any suggestions? thankyou...
I
It sounds like you need a ViewOverlay. This is the API documentation.
ViewOverlay is usually tied to a single view, but if you wrap it in a fragment, you should be able to attach it to each view in your application. This should create the effect of an of an application scoped overlay.
There may be a more elegant way of doing this, but I am not aware of it.
EDIT: You can also wrap your layouts inside a frame layout(s) along with a seperate nested view (the view that you want to keep on top of the stack).
Frame layout creates a 'stack' of inner views. If you use this approach, you can programmatically ensure that there are exactly two views present and visible as children of your frame layout at all times. one will be the layout tied to your current activity. The other will be the view that you want to be overlayed.
I know that the term 'programmatically ensure' is vague. This is because there are many ways to make this happen. It is up to you to decide which way best suits your needs.

Android Best Practice: Dynamically adding buttons to a ViewPager or Pre-Instantiating Them?

So I have a question about best practice for dynamically creating and sizing buttons within a ViewPager, based on a changing external state.
Essentially, I have a scrolling view and I want my ViewPager to contain a number of buttons of a specific size and count depending on what part of the scrolling view is currently visible.
My question is about deciding the best implementation of this feature, I see two options: would it be simpler to
Constantly create and scale new buttons whenever the scrolling view moves
Make the viewpager itself contain a scrollview and fill it with all of the pre-scaled buttons on app startup. Then, whenever the user scrolls the main scrollview the viewpager's scrollview (which contains the buttons) will scale programatically
Any ideas on which would be the simpler and more robust system?
Not much of an answer but I will leave a comment for ya! Basically you can do it either way, both aren't to difficult to accomplish, however I would probably go the dynamic route because it will always scale correctly. Doing a set amount will only work until devices become larger, or if you are targeting tablets or tvs then it will start to become extremely messy in the xml file for the layout. Dynamically adding also gives you far more control and saves time later on, you can simply change a number and have 100 more then going through and manually adding even 10. Hope this helps!

Create a view class that is a combination of two views Android

In my app, I have a screen that displays some images next to text. These images are downloaded from the internet, so there will be some latency in displaying them. Right now I have an ImageView and a ProgressBar overlaying each other, and toggling the visibilities when the Bitmap becomes available. Is there any way to combine the two into one class that will handle it all in case I want to use this somewhere else?
One way to go about solving the problem is to make your own custom view which extends ProgressBar and draw the image in the ondraw(Canvasn canvas) using a Rect. That way, your image can be embedded in your view and you can always make it reusable by allowing your self to set the image via a setter/resource xml files which specify the attributes that go along with your custom view. Here's a reusable ProgressButton that I wrote that maybe of use to you, it shows how I did something similar to what I described (it's one which I think works well):
PregressButton
Yes there are a number of ways to combine widgets into a single custom class. Have a read of Custom Components. This should help you decide which approach you want to use for your situation.

View different images depending on what item in my list view I click

I'm fairly new to Android programming and I've got this project I need to finish and I'm currently stuck.
I've got a standard listview in a Menu class with an array containing around 20 different elements. So what I want to do is load images in an imageview depending on which item in the listview I click, and since I'm a beginner the only idea I had was to make a new activity for each imageview which seems like a pretty bad way to do it since I'd need about 20-30 new activities..
To sum things up what I want is:
Code for making ONE activity that will display a different image depending on which item in the listview I click, probably pretty basic coding I want as simple solution as possible.
If possible I'm also looking for a solution that includes an SQLite database that stores the URL of an image and then display it in a single activity, also depending on which item I press in my current listview.
(I hope you understand my needs, and if you need I can also post my current code for the Menu class if it helps you help me) Or you can just show me a different way to make this work, I appreciate every answer! Thanks in advance!
NOTE
And please keep in mind, I'm a noob at Java and Android so keep it rather simple or at least explain what you do.
When you click on a list item, display the image in another view in the same layout, unless you want the image to take up the entire screen real estate. If you want it in the entire screen, go to a new Activity by sending the activity an Intent.
Activities are the "controller" of your application. They interact with the visible UI and the input from the user. You don't need a separate activity for each image, just an activity that's associated with a "place" in the UI (an ImageView) where you'll display the image.
I'd start by adding the images as resources under res/drawable before going on to databases.
You are going to have to do most of this yourself. There really isn't any substitute for taking the time to learn Java and Android. There are several tutorials and Android University classes under the Resources tab in the Developers Guide; I suggest you do all of them.

Android layout in java code

i'm making an app that requires indefinite textviews and images. i'm trying to implement a Pulse News app UI but having a hard time implementing one. so i thought of an idea to make a UI like that with the use of textviews, imageview and horizontal scroll view.
textview string values are from parsed xml online and images or the imageviews will be images from a specific directory in the sdcard that my app is using.
can anyone give me ideas how can i do it without using an xml layout or is there any or other options or ways for doing this? thanks...
You can create a viewgroup with one textview and an image. Then it can be added dynamically to your layout many times. This can be done by creating objects in a loop. You can change the content in each viewgroup at the time of inflation.
though i dont know what exactly how pulse new app looks like, but by going through your question (horizontal scroll view in particular) I guess you want to implement a "Gallery" type implementation where in you can swipe left/right on page basis.
If my assumption is correct then you will like to see to ViewPager of android backward compatiblity pkg.

Categories