Develop Reference

Imageview down the performance of my app

I am working on an Android app where, once a user clicks a login button, the app launches an AsyncTask to verify account details with a remote server. That part works fine by itself and doesn't make my app slow. However, when you click the login button, it launches a second activity where I have 4 ImageViews. When I added that part of the app, it became significantly slower (from less than a second to about 5 seconds loading time). I load the images into the ImageView from the XML layout file directly, so I'm not sure what I'm doing wrong.
My question is that do ImageViews make your app slow, and if so, how do you optimize their performance?

I was working my own app when I actually experienced this too. The reason is because if the files are to big they take a while to load into memory and set as the Image View. There is two ways you could really sort it out.
1: Get a smaller version of the picture. Smaller pictures come up faster and aren't prone to an OutOfMemory exception which kills the app :(.
2: A better way is to use the Picasso api. I used this APIs to add images in list views, expandable list view with pictures in them. The app was fast and fluid :)
Picasso's api would be your best bet ant it is easy to implement.
Edit:
Here is the link to the site to get the APIs :)
Picasso

The only way I could figure this out is to create an image in photoshop that has all the buttons laid out where you want them on top of the image. Interpret it into your app and put regular buttons over top of the imagebutton pictures that you placed onto your background image. Set the size accordingly to your images of your buttons and then set the background of each button to #null so they aren't seen. Now trying to figure out how to interpret this into orientation view even though I don't think I'll be using orientationview. OH AND CHANGED THE EXTENSION TO A GIF TO SAVE ON DATA RATHER THEN PNG.
Hope this helps I'm sort of new at coding on android as I have lots of experience with HTML .
Cheers
THANKS FOR THE DOWN LIKE I WAS SORT OF NEW AT THE TIME OF NOT KNOW OTHER WAYS TO SET THIS... THANKS THOUGH, MORONS

Why use ImageView when we have WebView?

This might seem to you guys as a stupid question, but it comes into my mind so many times:
Why is there an ImageView in Android? We have a WebView, which is capable of displaying images, and so much more stuff. So why would you provide an ImageView as well? Maybe there is some fundamental reason for this, but I just don't see it. Whenever I want to use some media, I try to use a WebView, because this allows me to change the type of media if I wish to do so, and I do not need another Type of View.
So to not make this question to broad, let's bring it down to this:
In which scenario does an ImageView have big advantages over a WebView?
EDIT
And a second question:
If I have some audio, some html-text and some pictures, which are stored locally on my device, would I use one WebView to display them, or would I use one Type of View for each Type of media?

WebView is a much more expensive widget to use, in terms of memory consumption, than is ImageView.
The reason for the memory cost of WebView is the fact that WebView is powered by a fairly complete copy of WebKit. WebKit is an open source Web rendering engine that forms the heart of major Web browsers, such as Chrome and Safari. While the version of WebKit that lives in Android is one optimized for mobile use, it still represents a fairly substantial code base, and rendering complex Web pages takes up a fair amount of RAM (as anyone with lots of browser tabs on their desktop knows all too well).

FACT: The WebView implementation is such that it will consume more memory if used to download & display images. Always. Also, ImageView has special methods / XML tags for cropping, resizing, scaling & manipulating images (which WebView doesn`t).

A person has a image in the gallery. The persom wants to show it inside the app. What will it do?
Go and host it on an online image hosting website and then pass the url to the WebView?
That ain't a cool Idea.. and people and Google understand that.

Basically image view using for showing image from gallery , drawable or url.Webview for handling or showing web content or html kind of thing.

Well ImageView consumes less memory. ImageView can change the image display options.
ImageView can display images from different sources like "Resources, drawables".
WebView mainly for displaying html pages.

Best Way to Animate images frame by frame in Android

I have 3 sets of 50 images and I have to create the animations for each set of images in Android application. I am able to create a simple application which animate first set of 50 images using the below method,
Added Animation-list xml in drawable folder and called it using frameAnimation.start().
This method didn't work until I kept the following "android:largeHeap="true" in manifest file.
I am not sure whether this is the good way to animate the images (if we have more number of images and each image of more size like 60 KB. Image is JPG format) or not
I browsed and I found that, if we are able to clear the memory and if we are able to maintain less number of images in memory, then our application will work very fine. So I want to know how to clear the memory?
Please let me know do I need to follow different method to animate the images other than I explained above, so that I can clear the memory.
Thanks for your help.

After looking into several posts and doing much research, I finally ended up modifying the images in Imageview programmatically to simulate frame animation. That way I am just maintaining three images in cache at any point of time (previous, current and next one). I hope that this will be useful to others.

It is not a good thing to process a large amount of images in a frame like manner in Android itself as it will trigger the dreaded "Out of Memory" exception.
Clearing the memory itself is not possible. The best fix for this is proper bitmap handling of the app.
I'm not sure but you might want to check on PhoneGap.
Its an HTML5 Engine that we used before to create a game.
By drawing into the canvas itself, we've recreated frame animation with it. It just requires WebDev skills though.

Animation in Android's WebView

As far as I know, swf's and gif's inside WebViews are not officially supported by Android, eventhough they work in my HTC Desire Device.
I'm building an app that it's all based in a WebView. What i did is code the 'app' as HTML, put it into the 'raw' folder and once the app starts, it puts all the htmls and images into a folder on the SD (if they're not there yet).
Now I need display some animations in there. I made them with Actionscript and I was glad that it seemed to work (Animations were 25KB each), but after a while publishing it, i got reports from people that coulnd't see the animation.
Then I patched them into a GIF (raised memory to 400KB-1MB each). At this point, I decided to take the gifs out of the raw folder, and download them from one server in the web the first time the app runs, so my apk doesn't get too big. But I get complaints again that people can't see it (then I found that GIF is also unsupported)
Google-ing and stackoverflow-ing I found that the only solution is to split those GIFs into separate images and show them with javascript one by one to create the animation. I guess this method is OK for small animations (like some face saying hello or something like that), but for whole animations.... It weights about 3MB per animation (when the swf was 25KB...). And I think taking 30MB (possibly more in the future for new animations) from user's data quota is not nice.
So:
Is there any other solution?
Are there lots and lots of phones that don't support SWF? and GIF? If they're not too many, I would consider putting on my app's description that the animations won't work if the phone has low memory (animations are not very important into my app)
Thank you very much,
Víctor
edit: Additional information: Animations are like this one.

So... I found the only way was to use HTML5 canvas animation, since surprisingly it is supported by many devices.
The animation is not as smooth as in a GIF-compatible device, but I rather make it accessible for everyone.
So, CommonsWare answered my 2nd question, but I will answer my 1st one: Yes, use HTML5. It didn't take a huge work, since JS can be Object-Oriented as well, and syntax is fairly similar to AS3.
And the best part is that the base code only weights 34KB (let's say the engine plus all the images), and each animation (in a separate file) weights between 1 and 2KB. That was awesome, I can put them all into my Android's raw folder.
Thank you very much CommonsWare for your comment.

Placing an draggable image onto PDF in Android

Here is my problem:
I need to create an interface, where a user could see a low-quality version of a PDF page, and choose a place to drop a small image onto. After that, I need to get the page number and the coordinates of the top-left corner and the bottom-right corner. I also need to make sure, that there is no way to move the image outside of the PDF.
What I could come up on my own, was to somehow convert the PDF to a bunch of images, which I could then show, and change pages, by just loading the image for the next page. And I could then create some sort of draggable on top of that, and read the coordinates.
So could anyone tell me how to get this done?
As a bonus, could someone help me with some tutorials, links and the sort, to resources that could help me with this?
From where I stand, this could be VERY interesting, but also very resource intensive, since the PDF's should be converted on the fly. Can it be done page by page?
Some technical specs:
Max file size - 4Mb, so the PDF wouldn't be awfully big
Min API - 8. I need it to work on Android 2.2

Ok, I've tried this out, and it all comes grinding to a halt on the PDF to image conversion, which with Open-source libraries takes about 10s for each page, making this a Non-option. A hat tip to Adobe for making it so fast with their app.