I'm fairly new to the whole GTK game and want to create an algorithm to take screen shot of all monitors.
I was thinking something along these lines:
gdk_display_manager_list_displays
each display can have multiple screens (screens means monitors?) so use gdk_display_get_n_screens to get monitors per display from 1
get root gtk window of all screens from 2
create new Pixbuf for each root gtk window for each screen from 3 with gdk_pixbuf_new
fill each pixbuf from 4 with gdk_pixbuf_get_from_drawable for each respective root window from 3 for each respective screen from 2 for each respective display from 1 (may need to gdk_drawable_get_size and gdk_window_get_origin for each for args to pixbuf)
gdk_pixbuf_get_pixels for each pixbuf
Is this a workable solution?
If you are sure cRootWin is not NULL and cWidth and cHeight are greater than 0 then you should check for some additional problem mentioned by the doc.
A wild guess is your program does not have enough memory to store the pixmap (typically 6 Mb). I would try to allocate the 12 Mb just to see if this is the case.
Related
I am trying to get the color of a pixel on my screen using node.js. I want it to be returned in RGB format, e.g. (255, 0, 0). My current solution is to use screenshot-desktop to screenshot my entire screen in JPG format, decode it to get the raw pixel data, and get the color of a given pixel. However, this lags out my entire computer for 1-2 seconds as it is taking the screenshot. This is unusable as I would like to do this multiple times per second. So my question is: How can I get the color of a given pixel on the screen, without taking a full screenshot?
I am using Linux with X11. There is an X11 library for node.js, so I asssume I should use that to get the pixel color, I'm just not sure how. If you could show me how to do it in C then I can easily use node.js to do the same thing.
Thanks!
Oh my gosh I just figured it out after posting this. I was using robotjs for reading the mouse position and I totally forgot it can do screen stuff too! So, the solution would be to do
var robot = require('robotjs');
var color = robot.getPixelColor(x, y);
X11 solution using x11 node library ( I am the author ):
query windows tree with QueryTree starting at the root window
get every child geometry using GetGeometry request
if your point is not inside any child, use current window id and get 1x1 pixmap from the current image: GetImage(format, currentWindow, x, y, 1, 1, planeMask) ( 2 for format and 0xffffffff for plane mask should work ). Make sure you calculate relative x y position as you travers windows tree.
if child window covers your point query children for that window and repeat again. Note that QueryTree returns windows in bottom to top stacking order so make sure you pick last one covering your point
Once you have 1x1 pixmap from the topmost window under your point - the buffer should contain only color bytes for your image, RGB order and bit mask might depend on red_mask, green_mask, blue_mask from display.screen[0].depths[visual].
If you cache "topmost window" between requests and only start from root when no match anymore the above solution might be much more performant then the one using robotjs ( although much more low level and complicated ) Good luck!
I want to make a splash screen that appears when i open the app and disappears after 3 seconds, with the image being shared with the next activity.
On smaller screens(for example Pixel 2) the animation works without problems, but when i try it on my OnePlus 6 or Pixel 3 XL, the image always clips to like 50dp below it's position right before the transition.
What could be the problem?
For anyone having the same problem.
The issue was that i was setting a color on the splash screen's frame background. If i didn't set any color, it would work fine.
I found a way around it by adding a view that expanded the whole screen and setting the color to the view instead.
I hope this will help someone eventually.
How to change the font size of text displayed at run time in the styles.xml in my application depending on the screen size of the device used.
I had the same problem. I wanted to get the same aspect text ratio on every screen. No dp nor sp worked for me. The only solution that works for me is to create a dummy textbox (not visible) at startup then get the textsize and multiply for some ratio (depending on what you actually want). This value should be used to set text size dynamically to your controls.
At least it works for me because the same aspect remains on every different screen.
you need to add in the text size via dimens.xml files depending on screen size.....take a look at this following Question on SO - Text size and different android screen sizes
You can go through this, I used the below method to scale texts on different screen resolutions and sizes.
To define a range of text sizes and a dimension programmatically through the support library, call the TextViewCompat.setAutoSizeTextTypeUniformWithConfiguration(TextView textview, int autoSizeMinTextSize, int autoSizeMaxTextSize, int autoSizeStepGranularity, int unit) method. Provide the text view on which it needs to be applied,the maximum value, the minimum value, the granularity value, and any TypedValue dimension unit (like TypedValue.COMPLEX_UNIT_SP).
I draw some text on screen using ID3DXFont::DrawText. This text should be displayed the same regardless of screen resolution.
For example, if screen resolution is low, text wrapped and when it is higher text is not wrapped. How can I avoid such situation? I want text size to be connected to screen resolution so if resolution is lower I want the text to be relatively smaller so that no wrapping happens. Is there any way?
Thanks in advance
Below is a logical solution. It doesn't have any of the code or procedures needed to make work in direct X but having done something similar outside of DirectX I wanted to share the logic
Working on whatever default screen resolution you want set the font to be the size needed.
Find the percentage of the screen height the font size you chose takes up.
Then having stored that value when you go to render again, in the final version of the program, calculate the font size based on the screen size and the percentage
What I was working in had functions like GetTextHeight and properties on the font size to allow you to set the height (which in turn set the font size appropriately). So if can find anything similar to this in DirectX than this could be a route for you to take.
So I have two images set to fill the screen - one at 320x480 (iPhone 3) and the other at 640x960 (iPhone 4).
img.png (320x480)
img#2x.png (640x960)
In Interface Builder, I have img.png set to fill the view (it shouldn't be filling the iPhone 4 view, though, right?), and when I build and run, it is notably too small.
So, when I do the opposite, setting img#2x.png as the img, a giant blue question mark fills the view. The project still builds and the image fills the screen, but is very pixelated as if it has been rescaled. It shouldn't have been rescaled, though, as it is the higher resolution.
Now using...
img.png (640x960)
img#2x.png (320x480)
I've also tried switching which file takes the #2x suffix, but that has not helped either. With the smaller file taking the #2x suffix, and setting the image view to img.png, it shows up way larger than the view canvas, but way too small when on the phone. With the smaller file still having the #2x suffix, I tried switching the view to the new img#2x.png and once again got the oversized, pixelated question mark in IB and a low res full-screen image when deployed to the phone.
I also made sure that my view size was set to 640x960 in the size inspector. What else should I be doing?
Don't use #2x when specifying the image name. Just use the base name of the image (so in your case, just img). iOS will do the magic behind the scenes to use the 2x version if it's on a retina display and the regular version otherwise (including when you use a xib to lay out your interface).
The displayed dimensions of the image will always be the dimensions of the non-2x image. The retina display just displays 2 pixels for every 1 which is why the scale is 2.0 and you have to double the dimensions of the original image. So your view size in IB should be 320x480.
Edit
If IB is being finicky, especially in Xcode 4, just try deleting the xib and starting over. Sometimes it gets a bit corrupted and doesn't know what to do with itself. I've had to do this on one or two occasions, and it seems that it worked for the OP as well.