How to change transparency of an imageview in certain area? - android

I'm trying to make a page of cropping profile picture. I have a crop frame which you can drag along. The image is transparent, or blurred, but within the frame, it is clear. The area within the frame will be your profile picture. I know how to set alpha, but I haven't come up with a way to set alpha within the crop frame. So this is the effect I want:
Any help would be great. Thanks!

You should probably think about having two ImageViews. One rectangular for the blurred photo and one circular placed on top of the first one for the crop preview.
When user selects a photo, you would create the blurred copy. It seems you already know how to move the photo within the ImageWiew, and so doing couple of calculations with the widths and heights of the ImageViews and the photo, should give you the correct positioning of the photos in both of the ImageViews to make them align.
Lastly when dragging on either of the ImageViews, adjust the position of the photo in both ImageViews.
This looks promising for circular ImageViews
ImageView in circular through xml
This might have something for efficient image blurring How to blur background images in Android
If you want a different approach, using OpenGL ES, you might be able to achieve realtime blurring outside of the circle with a pixel shader Shader for Android OpenGL ES. Possibly a more elegant solution, but probably not as simple.
I'm not exactly sure if you want blurring or transparency, but the solution will be very similar.

Related

how to make rectangle with custom imaged border so i can animate it later?

i want to make animated view as shown in the link
https://streamable.com/fpax52
there is an image selected and it should be rectangled and then animated with rgb
i have tried drawing canvas, but not sure that is proper way.
canvas?.drawBitmap(bitmap, 0f,0f,p)
it only drawes one image.
I also thought about creating multiple imageviews as rectangle but i think it is not good idea also.

Unity UI Image Center Crop

I am working on listView item in Unity and stuck at fitting the image properly in UI Image. I tried multiple things using Preserver Aspect Ratop, using Filled image type almost every thing but could not make it look fine. In android we call it center crop what i am trying to achieve. First image is with Preserve Aspect while the second one is without it.
What should i do to achieve it.
Thank you.
This is one way to do it that I can think of, using 2 images. The outer image is set at your desired size and have a Mask component:
The inner image is set at center of the outer image and scaled to fit the outer image (either programatically or by hand) It will be cropped by the outer image's mask and only display the area you want.

making UI layout with custom shape buttons

I want to make a layout like this. This app will be for my own use only i don't have much experience in graphics with android. I have draw these images and saved as PNG separately. I tried to put them in a layout, but i face to many difficulties with spacing and correct placing. But PNG is a rectangle and it clicks outside the image. So i think about preparing all possible situation and load all image as background. Touchable area rectangle(invisible) would be drawn inside button.
Is it a good practice to load image as a background when touch? I would have 16x4=64 backgrounds
What difficulties i can face in the future?
Should i stick to the black background and load separate buttons?
If above "Yes", then to draw background and image is better to resize image in pixels in a drawing SW like Corel? In my case 1280x720
1:
And the touch area would be something like this so i don't think it is possible to misclick it?
2:
With classic View, you won't be able to do non-rectangular view (you can draw want ever you want but your touch area is still rectangular).
The easiest way is to handle the onTouchEvent on a large View (fillin the screen with your image as background) with a View.OnTouchListener and calculate above which (fake) button you are.
For highlights you can use SurfaceView (could be the tricks #Frank.N.Stein talks about).
The hardest way is to use OpenGL graphics ... good luck for a someone who doesn't "have much experience [...]".

All of my content inside an backgroundImage

Basically What I'd like to try is to have all of my content in an image. I looked up some stuff but what they do is always use an imageView and text. But I'd like to use it as a background image.
Can someone give me an example how this exactly works? And how will the support be for using this with different screensizes, because the content always has to stay in the image?
To clarify what I want, I added an image. The green space is a background drawn in android xml, the white is the actually image and the text should be all of my content. I'd like to keep everything in the white, even if I get more edges.
The easiest way will be to have 3 layers
Top
Mask
Content
Image
Bottom
The mask will be an imageview (in your case only the green parts with the rest transparent).
The base image can be anything, but it would make sense that it complements the masking layer.
The content will be the tricky part. You will need to figure out the bounds of the masking layer so you won't go under the mask. I would suggest centering the content.
Alternatively, if the shape will change in size or is complex I would suggest using a canvas with a clipping pattern. On Android how do I make oddly shaped clipping areas?

Android LIVE Wallpaper approach?

I'm entirely new to Android development, and I'm interested in making a live wallpaper. I was thinking about looping a set of pictures instead of drawing the animation. Is this a possible approach? If possible is this a suitable or ideal way of doing it, does it eat up memory and would i need images with different resolutions because of the fragmentation?(hundreds of different devices)
Thanks in advance :)
Sure, it should be fairly simple.
The main part of the Wallpaper engine is the Drawing of course. You need to handle the drawing manually, there is no easy way to loop through images... you need to code it. You will have to continuously monitor the time which has passed and adjust the displayed image based on that. You are given a Canvas object to draw to and it is all done during run-time in code.
The Wallpaper engine class has a event called onSurfaceChanged which gives you the width and height of the Surface which you will be drawing to. It will be called everytime the screen dimensions change (like if the phone is put into Landscape mode for instance). You need to have code that will handle any combination of width or height for all the device types out there. You will need to decide if you are going to stretch, center, tile or crop (Or a combination of those) the source images to fit any particular screen size. I would recommend scale to fit so that the image is either taller or wider than the screen and center the image either vertically or horizontally (cropping the extra bits) once that is done. I personally just use one source size and resize it to fit. You can opt to use several source files if you want which is the recommended approach I believe, but it's a little confusing.
I would start by creating a Live Wallpaper which just draws something basic like a shape to the screen. Then work out how to display an custom image and take it from there.
Good luck
You will need to be very careful about memory if taking a frame approach to animation--probably will not be possible to animate full frames--much more practical to move sprites on a background. See, fr'instance: http://davidjhinson.wordpress.com/2010/05/19/scarce-commodities-google-android-memory-and-bitmaps/
what if you have a png frame animation that is set at a certain x and y position that sits in a spot on the background image, both would have to be rescaled

Categories

Resources