Develop Reference

How to save images with Picasso so there is no loading time?

I have an app where I display a quote and there is a picture in the background. When I click on a "next"-button, the next quote will be shown and the new image will be loaded. The loading takes around 0.5 seconds and has the image before as placeholder. But when I switch back, there is no loading time.
This means, the image is saved somewhere, so it does not need to be loaded again. Unfortunately, this is just temporarily. When I get to see the next 5 pictures and go back to the first one, the first picture needs to be loaded again. So I tried loading all the pictures in the beginning (it is just 25 pictures), like this:
Picasso.get().load(backgrounds.get(1));
Picasso.get().load(backgrounds.get(2));
Picasso.get().load(backgrounds.get(3));
Picasso.get().load(backgrounds.get(4));
Picasso.get().load(backgrounds.get(5));
Picasso.get().load(backgrounds.get(6));
Picasso.get().load(backgrounds.get(7));
and when I click on my "next"-button, I use this:
Picasso.get().load(backgrounds.get(counterBackground)).fit().noPlaceholder().into(background);
But both things without the expected effect. The images need a loading time around 0.5 every time and "noPlaceholder" doesn't work like expected, the placeholder is still there.
So, does someone know how to cut the loading time? Like, how to load all images in the beginning?
Thanks for every answer!

You can create cache while using Picasso, this will lead to quicker loading times (as long the images are cached
Picasso picasso = new Picasso.Builder(this).downloader(new OkHttpDownloader(getCacheDir(), 250000000)).build();
Picasso.setSingletonInstance(picasso);
source
You can use indicators to see from where the image is loaded by using
setIndicatorsEnabled(true)
source
You can also use callbacks to have an indication when the image is completed loading
you can see more details here
Edit
You can use
Picasso.get().load(R.drawable.pic).into(imageview)
I think it will work also for mipmap, usually mipmap are used for errors / place holders for your resources (if you are not using drawables)
2.
You can create your own policies about how to cache/load your images
Link

Getting pixel position of a text in an image

I am working on a research project.The scenario is this.
I am taking the screenshot of my desktop and then I process it using an API to get the position of a certain text on my Desktop.e.g , say I have the browser open on my desktop and I am on stackoverflow.Now I want to search the position of the logo stackoverflow on the screenshot taken.Then I want to simulate a click on it.I am using Java platform.
Now I have 2 questions:
1)Is there any free API(OCR) which I can use to process the screenshot to fetch text position (or can be done by some trick) and gives good results.
Or Any way you can suggest that I can use (instead of taking screenshot and processing it) to get the position of any text on the screen.
2)How can I simulate the click on the screen using the code by a background program running(I mean I have done it in Swing and other language UIs but this time its different as Now I want to click on the screen.

If I understood you right you want to move your mouse and click on the screen. That not that hard you could use the robot class from Java!
For example:
Robot rob = new Robot();
rob.keyPress( KeyEvent.VK_ENTER );
or what ever, there are so much bottons and movements you could with it. A list of all methods you find here.
And your other question I can't answer. I think there is no API that is able to search a text and give you the position. But what I know is that the robot class is able to capture the screen and put it into a BufferedImage. With it you could compare two pictures.
Maybe you could get use of this but I don't know if it is what you search.

Android how to do image screen slide?

I'm building a very basic gallery on android, it shows the last image on the camera folder and the user can slide left to see the previous one.
I finished an implementation using a viewpager, and a pagerAdapter using sampleSize to scale images. My problem is that the implementation is nowhere as efficient as the default gallery app, every time you slide an image you have to wait around 200ms for the next one to load. So basically my idea on how to implement it is not working out.
How can I do this efficiently, and if possible with an implementation that allows zooming in and out later on?
This looks promising but I don't know how to implement it with files instead of drawables
http://www.androidviews.net/2012/11/photoview/
EDIT:
I've managed to improve speed a bit using photoview (a hacked viewpager), however it takes too much to convert the filepaths to bitmaps or drawables.
I have tried these two methods suggested by dilix and iDroid Explorer:
// Method A
Drawable d = Drawable.createFromPath(imagePath);
imageView.setImageDrawable(d);
// Method B
Bitmap myBitmap = BitmapFactory.decodeFile(imagePath);
imageView.setImageBitmap(myBitmap);
But both produce error Bitmap too large to be uploaded into a texture. I need to get the image to the imageView as fast as possible and somehow bypass this error and maybe I'll get a decent speed. Right now I'm scaling the images and converting them to a drawable but it's not very efficient.

Check this awesome website : http://www.androidviews.net/
and maybe this is what you want: http://www.androidviews.net/2012/11/photoview/
It has page scroll, zooming and panning as you need
I have used it in my project with some modifications and lazy image loading. It is working exactly as you need.

See the official documentation for a great example that will walk you through using bitmaps with a viewpager efficiently. You should use a cache of the images that have already been loaded, and the images should be loaded outside of the UI thread. You also want to scale the image to the minimum size needed for your display (usually powers of two - note that the image won't always scale to what you ask it to!)
ViewPager also loads images in the background to prepare for the next slide, which is set with the setOffScreenPageLimit method (the default is usually good, I think it's 2.)
https://developer.android.com/training/displaying-bitmaps/index.html

I am not sure whether you got correct solution or not. But if you want to continue with your own implementation with your given link then:
http://www.androidviews.net/2012/11/photoview/ //this link is given in your question
And you can see this SO for how to convert file's path in to the drawable. Now, you get drawable of your specified file and implement on the link you have given.
I think that link will works nice.
Feel free to comments.

1)
This looks promising but I don't know how to implement it with files
instead of drawables http://www.androidviews.net/2012/11/photoview/
You have to store not list of drawables in you adapter, but links to files on your sd card and then load it.
2) But i can imagine that file instead of drawables won't be so efficient because to load from files you have to parse it from sd card.
I think you can save time by loading several images in your memory simultaneously (compressed) and when you swype to your othe image you'll already have the image and memory and while swyping you can start loading other image in memory.
When fling over the gallery you may not load images and load it after almost stopping.
It's the main problem: memory consuming vs performance.
UPDATE
I think better than exploring this by yourself will be exploring existing code of google gallery: https://github.com/CyanogenMod/android_packages_apps_Gallery
As i checked - they store cache (almost as i've said about loading multiple bitmaps) and store only resized images - seems to be efficient.

SMS Balloons / Long Chat Boxes

I want to be able to add a text-messaging balloon every time the user revives data from a HttpGet, I want it so that it looks nearly identical to the default Android text messaging UI. I'm fine with all the code, I just need a way to create the UI and create another text balloon every time data comes back from a HttpGet request.
Thanks ever so much, for the answering this questions and I'm sure there's an easy way to do it, yet I've found no way by using the 'ole Google.

I am doing something similar for my app am doing the following to achieve it:
You will need a 9-Patch-Image (a stretchable PNG, see here) that represents the bubble. You want to make the part stretchable that does not include the corners of the bubble. You can create the bubbles using an image editor of your choice (I'd recommend a vector graphics editor like Inkscape). Then use the 9-Patch editor included in the Android Developer Tools to transform the PNG image into a 9-Patch PNG.
Create a custom layout file for one bubble. Create a textview inside it, and add your bubble as a background resource. (android:background)
Use an arraylist with a custom adapter to inflate and fill your items.
So far, this will give you identical bubbles as background for all messages.
If you want to get fancy, you can create different bubbles for participants, and use the setBackgroundResource method in your Adapter to set the correct background.
Further, if you wish to align them left or right, like in the message app, you will need to add spacers to the left and right of your TextView in the layout file. I used FrameLayouts with a fixed width. Make sure to set their visibility to GONE.
As with swapping the different bubble colors, just set the visibility of the left/right spacer.

EditText background color

I have an Activity that consists only of a huge EditText, full screen.
To match with my app's colours, i changed the background color of the EditText. But although it occupies the whole screen, it only changes the first line. Everytime i press enter i go to a new line and that line gets the background i want.
What propertie can i set in order to do this? I just can't see it!

I would wrap the EditText with a View and set the background color on the View.

In order to change the background of those Views that come with a background already, its better to provide your own image, and then use patch9 for proper resizing
I hope that helps

#everyone:
While searching for a solution for this same kind of problem i found this page. While reading the solutions i thought to myself: "There must be a better way to do this, instead of making your own styles and widgetborders, etcetera, etcetera, ....
Therefore, i present to you: the 1 LINE OF CODE SOLUTION!!! No trolling.
<your-widget-component-that-has-a-background-color>.getBackground().setColorFilter(Color.<your-desired-color>, PorterDuff.Mode.MULTIPLY);).
It works like this:
"getBackground()" fetches the background from the component
"setColorFilter" will call a filtering on the background image itself
"Color." determines what color you want to pass onto the filter
"PorterDuff.Mode." sets the kind of manipulation you would like to do with the given color and the fetched background image. People with knowledge of image editing software (GIMP, Photoshop, ...) might recognise these modes. Basically, each mode has a certain effect on how the color is applied to the background image. to simply "override" the color of the image, while preservind it's gradients, borders and such, use "MULTIPLY"
I haven't profoundly read the PorterDuff class documentation, but honestly, ain't it a powerful bit of code?
With kind regards,

How to set the background color of an EditText widget:
editText.setBackgroundColor(Color.RED);