I check the Internet and see using ZXing to solve two-dimension code. But the code I do not understand.
PlanarYUVLuminanceSource source = new PlanarYUVLuminanceSource( data, width, height, dstLeft, dstTop, dstWidth,dstHeight, false);
What the meaning of the parameter?
I went to read the ZXing source code and I found the following (There was no constructor with boolean parameter in the end)
PlanarYUVLuminanceSource(byte[] yuvData, int dataWidth, int dataHeight, int left,
int top, int width, int height)
{
super(width, height);
if (left + width > dataWidth || top + height > dataHeight)
{
throw new IllegalArgumentException("Crop rectangle does not fit within image data.");
}
this.yuvData = yuvData;
this.dataWidth = dataWidth;
this.dataHeight = dataHeight;
this.left = left;
this.top = top;
}
When I read the code I understand the following (I have an assumption that the relevant data consider only as the area of the inner rectangle of where the QR code should be placed in the image).
byte[] yuvData - The byte array that contain the data of the image. All the data the one inside the rectangle and outside of it.
int dataWidth - The width of the data. The width of the data all the area outside and inside the rectangle.
int dataHeight - The Height of the data. The height of the data all the area outside and inside the rectangle.
int left - The left border of the rectangle. Or, how many pixels are outside of the rectangle from the left.
int top - The top border of the rectangle. Or, how many pixels are outside of the rectangle from the top.
int width - The width of the inner rectangle.
int height - The height of the inner rectangle.
Related
Is it possible to assign width and height to RadioButton in Android programmatically? I know we can do it by using scaleX and scaleY properties. What I am looking for is, if user gives a width and height in int, how can we apply to the RadioButton?
Try this:
myRadioButton.getButtonDrawable().setBounds(/* play around with the bounds */);
The documentation on the Drawable class says this is how you change a Drawable's size. Unfortunately, it's not really clear how it works, so you'll need to play around.
Since RadioButton, inherits from TextView, you can use myRadioButton.setHeight(int pixels) and .setWidth(int pixels) to set the size of the entire button area, but not the text nor the selection circle. To change the size of the content but not the overall area, you can use .setScaleX(float scale) and .setScaleY() you will change the text and selection circle, but not the button area.
So to change both the button area and the size of its contents:
int desiredWidth = 500; // Set to your desired width.
int currentWidth = radioButton.getWidth();
radioButton.setScaleX(desiredWidth / currentWidth);
radioButton.setWidth(desiredWidth);
And likewise for the height.
If you want to maintain the aspect ratio, set just the desired width and then:
desired_height = desired_width * current_height / current_width
Like this:
int desiredWidth = 500;
int currentHeight = radioButton.getHeight();
int currentWidth = radioButton.getWidth();
int desiredHeight = desiredWidth * currentHeight / currentWidth;
radioButton.setScaleY(desiredHeight / currentHeight);
radioButton.setHeight(desiredHeight);
radioButton.setScaleX(desiredWidth / currentWidth);
radioButton.setWidth(desiredWidth);
It appears that the scale is adjusted from the center, without adjusting the position, so you might have to change the position (maybe this will be moot if you use a ConstraintLayout--with a LinearLayout my buttons bled off the screen when I resized them this way).
I have a square ImageView which displays pictures of varying dimensions. I want to always maintain the original aspect ratio of the pictures and have no margin around the image (so that the image takes up the whole ImageView). For this, I am using the centerCrop scaleType on the ImageView. However, I want to make it so that if the top and bottom of the image are cut off (i.e.: the image is taller than it is wide), the image gets pulled towards the bottom of the container. So instead of having equal amounts of pixels cropped at the top and bottom, the image is flush with the top and sides of the ImageView and the bottom of the image has twice as much cropped off. Is this possible in xml, if not, is there a java solution?
You won't be able to do that with a regular ImageView and it's properties in xml. You can accomplish that with a proper scaleType Matrix, but tbh writing it is a pain in the ass. I'd suggest you use a respected library that can handle this easily. For example CropImageView.
You probably can't do this in layout. But it's possible with a piece of code like this:
final ImageView image = (ImageView) findViewById(R.id.image);
// Proposing that the ImageView's drawable was set
final int width = image.getDrawable().getIntrinsicWidth();
final int height = image.getDrawable().getIntrinsicHeight();
if (width < height) {
// This is just one of possible ways to get a measured View size
image.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
int measuredSize = image.getMeasuredWidth();
int offset = (int) ((float) measuredSize * (height - width) / width / 2);
image.setPadding(0, offset, 0, -offset);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
image.getViewTreeObserver().removeOnGlobalLayoutListener(this);
} else {
image.getViewTreeObserver().removeGlobalOnLayoutListener(this);
}
}
});
}
Note that if your ImageView has predefined size (likely it has) then you need to put this size to dimen resources and the code will be even simpler:
ImageView image = (ImageView) findViewById(R.id.image2);
// For sure also proposing that the ImageView's drawable was set
int width = image.getDrawable().getIntrinsicWidth();
int height = image.getDrawable().getIntrinsicHeight();
if (width < height) {
int imageSize = getResources().getDimensionPixelSize(R.dimen.image_size);
int offset = (int) ((float) imageSize * (height - width) / width / 2);
image.setPadding(0, offset, 0, -offset);
}
See also:
findViewById()
getResources()
I need to draw something like this:
I was hoping that this guy posted some code of how he drew his segmented circle to begin with, but alas he didn't.
I also need to know which segment is where after interaction with the wheel - for instance if the wheel is rotated, I need to know where the original segments are after the rotation action.
Two questions:
Do I draw this segmented circle (with varying colours and content placed on the segment) with OpenGL or using Android Canvas?
Using either of the options, how do I register which segment is where?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
EDIT:
Ok, so I've figured out how to draw the segmented circle using Canvas (I'll post the code as an answer). And I'm sure I'll figure out how to rotate the circle soon. But I'm still unsure how I'll recognize a separate segment of the drawn wheel after the rotation action.
Because, what I'm thinking of doing is drawing the segmented circle with these wedges, and the sort of handling the entire Canvas as an ImageView when I want to rotate it as if it's spinning. But when the spinning stops, how do I differentiate between the original segments drawn on the Canvas?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I've read about how to draw a segment on its own (here also), OpenGL, Canvas and even drawing shapes and layering them, but I've yet to see someone explaining how to recognize the separate segments.
Can drawBitmap() or createBitmap() perhaps be used?
If I go with OpenGL, I'll probably be able to rotate the segmented wheel using OpenGL's rotation, right?
I've also read that OpenGL might be too powerful for what I'd like to do, so should I rather consider "the graphic components of a game library built on top of OpenGL"?
This kind of answers my first question above - how to draw the segmented circle using Android Canvas:
Using the code found here, I do this in the onDraw function:
// Starting values
private int startAngle = 0;
private int numberOfSegments = 11;
private int sweepAngle = 360 / numberOfSegments;
#Override
protected void onDraw(Canvas canvas) {
setUpPaint();
setUpDrawingArea();
colours = getColours();
Log.d(TAG, "Draw the segmented circle");
for (int i = 0; i < numberOfSegments; i++) {
// pick a colour that is not the previous colour
paint.setColor(colours.get(pickRandomColour()));
// Draw arc
canvas.drawArc(rectF, startAngle, sweepAngle, true, paint);
// Set variable values
startAngle -= sweepAngle;
}
}
This is how I set up the drawing area based on the device's screen size:
private void setUpDrawingArea() {
Log.d(TAG, "Set up drawing area.");
// First get the screen dimensions
Point size = new Point();
Display display = DrawArcActivity.this.getWindowManager().getDefaultDisplay();
display.getSize(size);
int width = size.x;
int height = size.y;
Log.d(TAG, "Screen size = "+width+" x "+height);
// Set up the padding
int paddingLeft = (int) DrawArcActivity.this.getResources().getDimension(R.dimen.padding_large);
int paddingTop = (int) DrawArcActivity.this.getResources().getDimension(R.dimen.padding_large);
int paddingRight = (int) DrawArcActivity.this.getResources().getDimension(R.dimen.padding_large);
int paddingBottom = (int) DrawArcActivity.this.getResources().getDimension(R.dimen.padding_large);
// Then get the left, top, right and bottom Xs and Ys for the rectangle we're going to draw in
int left = 0 + paddingLeft;
int top = 0 + paddingTop;
int right = width - paddingRight;
int bottom = width - paddingBottom;
Log.d(TAG, "Rectangle placement -> left = "+left+", top = "+top+", right = "+right+", bottom = "+bottom);
rectF = new RectF(left, top, right, bottom);
}
That (and the other functions which are pretty straight forward, so I'm not going to paste the code here) draws this:
The segments are different colours with every run.
Here's what I need:
I have a Surface view that has a square (image view) on top of it. I need to capture an image, and crop out the area that was visible only within the square.
This code gives me decent results but specific only to some devices:
int width=(int)(bitmap.getWidth()*60/100);
int height=(bitmap.getHeight()*100/100); //dont change
bitmap=Bitmap.createBitmap(bitmap,150,0, width-55, height);
Is there any way I could generalize this code? Is there any other way to get what I need?
EDIT: This is how I got it to work-
Save the image from the surface view as a bitmap (This is very simple. There are many examples available on the internet that show how to do that)
Use this code in a function, and call it after the image is clicked
//bitmap is the object where the image is stored
int width = bitmap.getWidth();
int height = bitmap.getHeight();
int left;
if(width > height){
left = (width - height)/2;
}
else {
left = (height - width)/2;
}
bitmap=Bitmap.createBitmap(bitmap,left,0, height, height);
I'm new bird for the Android App, hope can get teach from expert. I'm now doing the checkers board game for my final project. I face the problem is, how do I set the coordinator for my board boxes with using the image button?
Do I am correct for using that way?
You could use a GridView to contain your board squares. Then you could simply bind an array of your backing checker square objects to the grid, and create your own BaseAdapter to display an ImageButton in each grid cell.
I would create a custom View and set it as the content background.
ie.
CheckerBoard board = new CheckerBoard(this);
setContentView(board);
In the above code, CheckerBoard extends View. Within the CheckerBoard class, you could have the view divided into an 8 x 8 grid programmatically using the width and height passed in. Then you could have that view paint your grid, while also binding each area to a two-dimensional array. It's kind of complicated to explain the hierarchy I have in mind, but check out this mockup:
public class CheckerBoard extends View {
#Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
height = MeasureSpec.getSize(heightMeasureSpec);
width = MeasureSpec.getSize(widthMeasureSpec);
// A checkerboard is a square; this keeps the view's
// length and width the same size.
width = (height > width) ? height : width;
height = (height > width) ? width : height;
this.setMeasuredDimension(width, height);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
//Log.i("VolumeGauge", "Size changed to " + w + "x" + h);
// This is where you divide up the view into 64
// pieces and paint them.
generateBackground();
}
Other methods here…
}
There is a LOT of stuff that goes into making this work properly, but the best resource I can give you is this:
http://mindtherobot.com/blog/272/android-custom-ui-making-a-vintage-thermometer/
It walks you through the process of creating a custom View.
Once you have the CheckerBoard created, it's just a matter of mapping each square to a two-dimensional boolean array (each element will be true if it is occupied by a playing piece), and then tracking the user's touch input on the screen.