Show text after file pushed

[npes87184]

Hi,

In this series, I add a text framework. User can use this framework to show text on screen.
After it, I use this framework to show file pushed.

imgur

Note:

Because the path of font file is difficult to specify in linux based system. I embed open-sans ttf to prevent loading font file failed.

Thanks.

[rom1v]

Thank you for working on this. I agree that some OSD would be better to report status/actions to the user (like FPS count #274 (comment)).

Because the path of font file is difficult to specify in linux based system. I embed open-sans ttf to prevent loading font file failed.

I'm not fan of embedding the font into the source code (I know that I did that for the icon, but it's ASCII-art readable, not an array of hexadecimal values). I'd prefer a separate font-file. By the way, unless we want a specific font (I think we don't), I think it should even use some default sans-serif font available on the system.

I added some inline comments on the PR.

Also, from a user point of view, I think that it is not very clear that the text is added by scrcpy (that it is not part of the device screen). I'm not sure how to improve that. Maybe one reason is that Android already displays notifications as toasts at the same location.

Events like "file pushed" could maybe printed in the bottom in some (overlay) "status bar" (a bit like in Firefox when we hover a link). Or as notification bubbles in the top-right (a bit like the result of notify-send mytext on Linux, ideally, they would also appear/disappear gracefully). (These are just things I have in mind, but I'm very bad at UI design 😉)

[rom1v]

This opens the font and draws the glyphs on every frame :/

IMO, it should create the texture and render the text the first time, then cache it (to be invalidated on resize though).

[npes87184]

Agree.

[rom1v]

(but it's racy, you should use an atomic instead)

[npes87184]

Yes, it will race. But the effect is just that it will delay notice that it needs to show text.

This trick added only because I notice the performance has some degrade. Maybe if we don't create texture every frame, we don't need this.

[rom1v]

But the effect is just that it will delay notice that it needs to show text.

It's a data race, so in theory the flag write may never be seen by the other thread.

#include <pthread.h>
#include <stdbool.h>
#include <stdio.h>
#include <unistd.h>

static bool keep_running = true;

void *run(void *arg) {
    (void) arg;

    printf("start\n");
    while (keep_running);
    printf("end\n");

    return NULL;
}

int main(void) {
    pthread_t thread;
    int ret = pthread_create(&thread, NULL, run, NULL);
    if (ret)
        return 1;

    sleep(1);

    keep_running = false;
    printf("keep_running = false;\n");

    ret = pthread_join(thread, NULL);
    if (ret)
        return 1;

    return 0;
}

$ gcc -pthread ub.c && ./a.out
start
keep_running = false;
end

$ gcc -O3 -pthread ub.c && ./a.out
start
keep_running = false;
// never ends

[npes87184]

Oops, maybe lack a volatile?

BTW, thank you for your example.

[rom1v]

Oops, maybe lack a volatile?

Or any synchronization fixing the data race (an atomic would probably be preferable).

[npes87184]

Ok, thank you.

I will try to fix these issues in weekend.

[rom1v]

The time is handled as the number of frames. But the framerate is (very) variable: it may be as low as 0 fps if the device screen is constant to 90fps (for example) if it changes a lot.

The "toast" delay should be based on real time instead.

[npes87184]

Agree.

[npes87184]

What should happen if time is up but the screen is constant? In current implementation, it will remain on screen until screen changed.

[rom1v]

IMO, the popup/taost delay should be independant of the device video. It should fade out after a constant delay (whether the device screen is constant or not).

[npes87184]

Thank you for working on this. I agree that some OSD would be better to report status/actions to the user (like FPS count #274 (comment)).

Because the path of font file is difficult to specify in linux based system. I embed open-sans ttf to prevent loading font file failed.

I'm not fan of embedding the font into the source code (I know that I did that for the icon, but it's ASCII-art readable, not an array of hexadecimal values). I'd prefer a separate font-file. By the way, unless we want a specific font (I think we don't), I think it should even use some default sans-serif font available on the system.

Yes, I also think that embed some binary in code is really ugly. However, as far as I know, there are not an easy and reliable way to get usable font cross platform...

I added some inline comments on the PR.

Also, from a user point of view, I think that it is not very clear that the text is added by scrcpy (that it is not part of the device screen). I'm not sure how to improve that. Maybe one reason is that Android already displays notifications as toasts at the same location.

Events like "file pushed" could maybe printed in the bottom in some (overlay) "status bar" (a bit like in Firefox when we hover a link). Or as notification bubbles in the top-right (a bit like the result of notify-send mytext on Linux, ideally, they would also appear/disappear gracefully). (These are just things I have in mind, but I'm very bad at UI design 😉)

Maybe style like notify-send is a good design?
(I'm very bad at UI design too :/)

[npes87184]

I have pushed new version, it includes:

1. Toast will fade out after a constant delay no matter the state of the screen.
2. Cache test_texture.
3. Prevent racing

Some missing parts:

1. UI/UX
2. Embedding font

BTW, windows lacks some dll now, I will fix it later.

[npes87184]

@rom1v

I find that in windows, to make this feature working, we need a lot of dll and it is annoy to use current method to manage a lot of dlls.
Do you have another good idea about this problem?

Thank you.