kandi X-RAY | CanvasX Summary
kandi X-RAY | CanvasX Summary
脱离Android模拟器,在Java程序中使用Android下的Canvas、Paint、Bitmap等Graphics类(提取自Android Studio)
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Currently covering the most popular Java, JavaScript and Python libraries. See a Sample of CanvasX
CanvasX Key Features
CanvasX Examples and Code Snippets
Community Discussions
Trending Discussions on CanvasX
QUESTION
My variables are:
canvasX
- This is the horizontal size of the canvas being drawn on. (user picks)1stX
- My first point, determined at random, withincanvasX
. (something like:random(0, canvasX)
)rando
- A random number to determine the distance the next 2 points are from1stX
.2ndXleft
- an equidistant point from1stX
to the left. (basically1stX - rando
)2ndXright
- an equidistant point from the 1stX to the right. (basically1stX + rando
)
I've got a canvas I'm drawing on and I want a point picked out with a random variable for x. I then want two more points but these need to have the x coordinate be equidistant from the first. I also want for these points to always be within the canvas.
So, if my canvas size is 1000, and my 1stX
is 100, the max distance for rando
would have to be 100. same is my 1stX
was 900.
rando
is my problem, how do I figure out what that distance can be?
ANSWER
Answered 2021-Apr-23 at 18:10The simplest would possibly be the following
QUESTION
I have this design description to create:
Step 1: Default state is type on white background.
Step 2: Cursor tracks and you draw.
Step 3: If you fill the whole screen red, then cursor draw changes to white colour.
Step 4: You draw in white.
Step 5: If you fill the full screen with the drawing, you're back to step 1 with a full white background.
I have completed the task till Step 2 but unable to change color once entire screen is filled with red color.
So in short, Once the users fills the box with red color, I want to change the color to white. And in same way once the box is filled with white color I want to change it back to red.
Please check the codepen for code - https://codepen.io/chiragjain94/pen/dyOzqGy
...ANSWER
Answered 2021-Feb-21 at 01:24You need verify each pixel value and compare to red color or white color (RGB value).
Use the ctx.getImageData to get array of color. This array have a length = width * height * 4 size, cause it save 4 information: r, g, b and a. So turn a loop with i+4 interation. In interation you can work with i, i+1 and i+2 to get r, g and b.
Red is R=255, G=0, B=0 White is R=255, G=255, GB=255
QUESTION
Shouldn't field
be undefined on line 50? It was my understanding that inner nested classes did not have visibility to outer classes, as I ran into on line 65... Just seems kind of inconsistent and I would love to have a better understanding of the outer nested classes visibility to avoid any confusion in the future.
ANSWER
Answered 2020-Dec-18 at 03:32I've write very simplified example:
QUESTION
I found a beautiful script for making a snipp from actual window here on Stackoverflow and I'd love to use it in the personal application that I'm creating. But I think I'm missing something big here and I don't understand why it's not working.
...ANSWER
Answered 2020-Dec-11 at 00:06I'd say try
QUESTION
I apologize for the code, it's in a state I'm actively playing with.
In Konva JS, I'm creating labels. Which is basically a group, it has a shape and text element. The shapes are drawn dynamically from a database, and each db row has the coordinates, the shape (square, circle etc), size and rotation. These are multiplied by a scale depending on screen size. I had a working solution, which I've been using for weeks, but I also have a function that changes the shape of a shape. So I press a button, it updates the database (e.g changes square to circle) and then redraws the canvas. Because going from a square to a circle changes from a shape that's drawn from the top left to one that's drawn from center, it messes up the coordinates. I decided to switch to drawing rectangles with an offset of width/2 so that rectangles are drawn from the center too.
I have subsequently kept breaking it further and I now can't get text centered at all. I need text centered regardless of shape, size or rotation.
current code
...ANSWER
Answered 2020-Dec-05 at 11:05I slightly rewrote your creation routine; seems working well like this. The essence here is that shape + label are grouped together and global [scaled] position is applied to those groups, not individual graphic elements.
Code:
QUESTION
I'm making and UI for a Tangram (puzzle with different polygons) using tkinter in Python and I'd like to keep track of the coordinates of each point of each polygon when they move around my canvas.
To do so, I created this class:
...ANSWER
Answered 2020-Nov-30 at 20:17canvas.bind('', self.start_movement)
canvas.bind('', self.movement)
canvas.bind('', self.stopMovement)
canvas.bind('', self.rotate)
QUESTION
I tried to see the difference between a window coordinate and a canvas coordinate by giving a canvas a callback that prints the coordinates of a mouse click in both types. I expected the two types of coordinates to have different values, but they didn't. Also, I tried to pass window coordinates to the find_closest
method which, as stated in the documentation, accepts canvas coordinates, and there was no error.
ANSWER
Answered 2020-Nov-21 at 18:50You only need to do the conversion if your canvas is able to scroll. Otherwise there's a 1:1 mapping between window and canvas coordinates.
You can see this by adding the following code to your example, at some point after creating the canvas:
QUESTION
ANSWER
Answered 2020-Oct-19 at 20:05The border has a thickness, which is easy to forget. If you draw a box which is X wide, its left and right border are in addition to the width of X.
So if you do NOT fill the interior, you get this nice appearance (left), but if you FILL, you get this ugly appearance (right).
When you draw a grid of these squares, each one covers over the right-hand and bottom sides of previous squares, so that it is not obvious what is happening.
Unless you redraw one that is not the last of the list, as I have done here (bottom-middle). Then it becomes obvious that something is wrong.
Here is the code to reproduce the above figures, and below I recommend a solution.
QUESTION
Although the code work just fine if we draw the rectangle without scrolling the canvas or page. But in case we do scrolling, the rectangle do not appear on the screen from the point where we start to drag the mouse.
...ANSWER
Answered 2020-Aug-22 at 10:42Using this answer to compute the mouse position, it works great. It takes the scrolling into consideration.
QUESTION
I've got a Javascript file which draws a canvas with circles. If I click on a circle, the color must change. This works, but the eventHandler fires many times with one click. Because of this, the program lags a lot. How do I improve this?
...ANSWER
Answered 2020-Jul-27 at 09:01Currently, you are adding an event listener on every draw cycle because of where you're calling addEventListener
. If you instead move addEventListener
to the constructor of the circle, it will only be attached once per Circle object (in your case, 64 times):
Community Discussions, Code Snippets contain sources that include Stack Exchange Network
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Install CanvasX
You can use CanvasX like any standard Java library. Please include the the jar files in your classpath. You can also use any IDE and you can run and debug the CanvasX component as you would do with any other Java program. Best practice is to use a build tool that supports dependency management such as Maven or Gradle. For Maven installation, please refer maven.apache.org. For Gradle installation, please refer gradle.org .
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