how I can make a custom clickeable area/button? For example, If I have a semicircle as the image below, how I can make the whole area red, blue or gray are clickable and independent?
Thank you for your advices.
you can use this example :
https://mega.co.nz/#%21lMUHQTAQ%21Tr3i-3iYnsNt8-2DshNbwBAObJkZFU7NJGYMu5RBxGw
Or :
https://mega.co.nz/#!0M9HUTKZ!cMe8iDz4BnV5aPc92eIRTG8JHqMHSntSUi_0YelfU7M
As already mentioned – make the whole view as one, and calculate in the onTouchlistener().
I would transform the touch coordinates in polar coordinate system (polar angle, radial distance).
Then just check if the radial distance is between inner circle and outer circle radius. If it is, then some button was clicked. You can determine which button was clicked from polar angle (e.g. 0-120 degrees = red button, 120-240 degrees = gray button, 240-360= blue button).
Related
I want to draw arc on canvas with progress percentage on circle and need to perform click on both the color (blue and green).
How to make click listener for the same.
You have two circle for grean line
Two circle makes green area(difference of inner and outer circle) say circles G1(inner), G2(outer)
first find circles sector area of G1 and G2 say GS1 and GS2.
Now find touch point form on touch event say p1. If p1 lie in GS2 but not in GS1 than you have touched on green line
Similarly you have two circle for Blue line and you can find touch point
See this link also - Efficiently find points inside a circle sector
I have created a Class extending View class. I have set the background in XML which is being called as setBackgroundDrawable(getBackground()) in my onDraw() method. This background in 3 concentric circles.
I have the radius for each concentric circle and i am drawing a small orange colored touchCircle when user touches in any of the ring using canvas.drawCircle(touchX, touchY, touchRadius, mTouchPaint); .
My question is i want to show a glow effect on both sides of the touch Circle within the ring(on which onTouch operation is performed). That means, suppose if the user touches in 3rd ring, a glow effect will be produced of some color around the touchCircle. It will travel from the touch circle to some distance(on both sides of touchCircle) within the ring and then fades out.
I have calculated the angle substended by the touch cordinate with respect to centre(0-360 degrees). My thinking is i will increase/decrease the angle (for left and right glow). But i am confused as in how the glow effect will be produced in the background image.
Can anyone please guide how to proceed further on this .
I want to create a semi doughnut shaped button which is only clickable in the region where it is visible and not in the the whole rectangular region.
http://i.stack.imgur.com/MKD45.png
I want clicking to affect only this blue region.
You can do this by grabbing the Bitmap representation of the Button, then testing the x/y pixel's alpha value.
To get the bitmap for a button:
Bitmap buttonBmp;
button.setDrawingCacheEnabled(true);
buttonBmp = Bitmap.createBitmap(button.getDrawingCache());
button.setDrawingCacheEnabled(false);
I'd recommend only doing this once, and saving the results, that way you're not creating a new bitmap every time you touch the button.
Then you override the Button's onTouchEvent so you have the local x/y where the user tapped. If the alpha in that spot is 0, you have a non-clickable area. It's not as simple as an onClickListener, but it should do the job.
This way you can use any arbitrary shape, not just a doughnut. Colors, textures, whatever.
I'm not entirely sure on this but I think this scheme would work. Create an image view in your layout to display the picture and make it clickable via an onTouchEvent. This way you can get the coordinates of the click. Check to make sure that the click is within the inner and outer radii and if it is, do the given response.
Here are a few calculations that will need:
Center of circle
-Assuming the center is the very bottom of the image, this will look something like this(not necessarily exact methods)
centerX = img.getX() + img.getWidth()/2;
centerY = img.getY() + img.getHeight()/2;
Remember that screen coordinates go from top to bottom and from left to right.
Find the distance away from the center where the click occurred
Dx = click.getX() - centerX;
Dy = click.getY() - centerY;
D = Math.sqrt(Dx^2 + Dy^2);
Then all you need is to check if the distance is within the radii(not sure how to get the exact radii here, may just need to guess and check. An alternative may be that the top of the semicircle is the top of the picture and then the max height with be the outer radius.)
if(D<=outerR && D>=innerR)
respond();
I need to apply click/touch events for only visible part of the View. Say for example a image of size 200X200. Apart from center 50X50, remaining part is transparent. I want to get touch events only for that 50X50 visible part Not on remaining transparent part.
In above image (its single image), only inner Diamond has got visible part. Apart from that Diamond is transparent area. So, if I touch Diamond then only I want to do something else ignore.
Edit :
Rachita's link helped me. I gone through that link and got idea how can I implement. But I could not understand some constants like 320, 240 etc while creating Points. In my case, I know the Diamond (in above image) x and y Ponits (hard coded values asctually). So, using those how can I determine, whether I touched inside Diamond or outside?
my Diamond points are as below
pointA = new Point(0, 183);
pointB = new Point(183, 0);
pointC = new Point(366, 183);
pointD = new Point(183, 366);
Edit :
Finally got solution from Luksprog. Its based on checking touched point pixel color. If color is 0 means, you touched transparent layer else you touched some colored part of the image. Simple, but very effective. Have a look at it here.
AFAIK you can not implement this with onclick listener or my any other direct way .You will have to use onTouchListener .
Firstly set your view dynamically at a specific (x,y) position using this How can I dynamically set the position of view in Android?
Calculate the region your diamond will occupy (you should khow the size of image inorder to calculate area of diamond)
3.Trigger a action in onTouchListener only when x, y fall in the required region. Use How to get the Touch position in android?
check this link to calculate if a given point lies in the required square
EDIT
To understand the coordinate system of android refer to this link How do android screen coordinates work?
Display mdisp = getWindowManager().getDefaultDisplay();
int maxX= mdisp.getWidth();
int maxY= mdisp.getHeight();
(x,y) :-
1) (0,0) is top left corner.
2) (maxX,0) is top right corner
3) (0,maxY) is bottom left corner
4) (maxX,maxY) is bottom right corner
here maxX and maxY are screen maximum height and width in pixels, which we have retrieved in above given code.
Remember if you want to support multiple devices with different screen sizes,make sure you use a relative value for x,y ie some ratio of screen height or width ,as different devices have different ppi
Check if touched point lies in the required polygon
I thinks these link might help you determining if the point touched (you can get x,y from onTouch event eg.event.getX()) lies in the required polygon whose points you have mentioned in the question . determine if a given point is inside the polygon and How can I determine whether a 2D Point is within a Polygon?
I want to achieve a tilt effect when a button is clicked, on Android OS.
Tilt Effect: Not the whole button will be seen as pressed. Only the part that touch event occured should seem to be pressed.
Is this easily possible on Android?
A simple way would be to use canvas draws to draw 4 sided shapes.
Consider each 4 corners. The "untouched" rectangle would be full size the touched rectangle would be smaller.
You just need to draw your four sided shape using a point you calculate for each part of the rectangle. You can get the touch position, then figure out how much "weight" to give each point.
to calculate each corner, you need to figure out how much "weight" to give the touched coordinate, and how much "weight" to give the untouched coordinate. If you touch the top left corner, that corner would use 100% of the touched coordinate, and the other three corners would all use the untouched coordinate.
If you touched the top middle, you would get a shape like this:
We can calculate the corners for any touch spot, by calculating how far from the corner your touch is
float untouchedXWeight1 = Math.abs(xt - x1)/width;
//maximum of 1, minimum of 0
float untouchedYWeight1 = Math.abs(yt - y1)/height;
float untouchedWeight1 = (untouchedXWeight1 + untouchedYWeight1)/2;
//also maximum of 1, minimum of 0
float touchedWeight1 = 1 - untouchedWeight1;
so with those weights, you can calculate your x and y positions for that corner:
x1 = xUntouched1 * untouchedWeight + xTouched1 * touchedWeight1;
y1 = yUntouched1 * untouchedWeight + yTouched1 * touchedWeight1;
Then do similarly for the other 3 corners.
I've created a first draft here : https://github.com/flavienlaurent/TiltEffect
In a second step, I will make it usable with Button etc.
Unfortunatly, I didn't use the very good (but too mathematical for me) answer of HalR