Fix active window not working on the framebuffer

[weihsinyeh]

Remove the inefficiently function twin_active_pixmap(). This function finds the currently and previously active window pixel map by traversing the list of pixel maps. This function will be called every time the screen needs to be updated. Set the active variable of the window only when the window's event TwinEventButtonDown is triggered to avoid redundant operations. Additionally, implement the function twin_window_active_paint() to only repaint the title bar instead of calling the function twin_window_draw() to indirectly call the function twin_window_frame to repaint the title bar of the window.

Close #92

[shengwen-tw]

Looks legitimate to me, but since I am not familiar with recent developments, I would like to see if others have different opinions.

[huaxinliao]

I confirmed that fbdev can run on a VM with Ubuntu 24.04 and a Pi 3B. Below is the output from the Pi 3B.

test.mp4

[weihsinyeh]

The title bars of the active and inactive window don't display on the video.

[ndsl7109256]

The reason that the title bars don't show is because you need to determine the trajectory you want to paint first and then use twin_paint_path or twin_paint_stroke to fill the graph or draw the border.

I think the twin_window_active_paint would be like

static void twin_window_active_paint(twin_window_t *window)
{
    // Ignore the above
    twin_path_t *path = twin_path_create();
    twin_path_move(path, c_left, c_top);
    twin_path_draw(path, c_right, c_top);
    twin_path_curve(path, c_right, w_top + t_arc_1, c_right - t_arc_1, w_top,
                    c_right - t_h, w_top);
    twin_path_draw(path, c_left + t_h, w_top);
    twin_path_curve(path, c_left + t_arc_1, w_top, c_left, w_top + t_arc_1,
                    c_left, c_top);
    twin_path_close(path);
    if (window->active) {
        twin_paint_path(window->pixmap, TWIN_ACTIVE_BG, path);
        twin_paint_stroke(window->pixmap, TWIN_ACTIVE_BORDER, path, bw_2 * 2);
    } else {
        twin_paint_path(window->pixmap, TWIN_INACTIVE_BG, path);
        twin_paint_stroke(window->pixmap, TWIN_INACTIVE_BORDER, path, bw_2 * 2);
    }
}

[weihsinyeh]

Thank you! It seems that using the "twin_window_frame()" function directly is still the better option. Originally, I thought this just changed the BG and border colors. But since there is no path record, it is not sure where to apply the colors.

[ndsl7109256]

How about adding a twin_path_t *label_path member to twin_window_t? In twin_window_frame, you could initialize the path, and in twin_window_active_paint, determine the color to paint when the top window changes. Then you can still apply the colors in the same logic.

static void twin_window_active_paint(twin_window_t *window)
{
    twin_fixed_t bw = twin_int_to_fixed(TWIN_TITLE_BW);
    twin_path_t *path = twin_path_create();
    twin_fixed_t bw_2 = bw / 2;
    if (window->active) {
        twin_paint_path(window->pixmap, TWIN_ACTIVE_BG, window->label_path);
        twin_paint_stroke(window->pixmap, TWIN_ACTIVE_BORDER, window->label_path, bw_2 * 2);
    } else {
        twin_paint_path(window->pixmap, TWIN_INACTIVE_BG, window->label_path);
        twin_paint_stroke(window->pixmap, TWIN_INACTIVE_BORDER, window->label_path, bw_2 * 2);
    }
}

static void twin_window_frame(twin_window_t *window)
{
    /* Ignore the above */
    window->label_path = twin_path_create();
    twin_path_move(window->label_path, c_left, c_top);
    twin_path_draw(window->label_path, c_right, c_top);
    twin_path_curve(window->label_path, c_right, w_top + t_arc_1, c_right - t_arc_1, w_top,
                    c_right - t_h, w_top);
    twin_path_draw(window->label_path, c_left + t_h, w_top);
    twin_path_curve(window->label_path, c_left + t_arc_1, w_top, c_left, w_top + t_arc_1,
                    c_left, c_top);
    twin_path_close(window->label_path);
    twin_window_active_paint(window);
}

[weihsinyeh]

OK, Thank you! we can try which one can work on framebuffer.

[huaxinliao]

Here's the output from 512a891 on the Pi 3B.

drm.mp4

[ndsl7109256]

Why did you change this function from static to non-static?

[weihsinyeh]

This is because, originally, in order to call twin_window_frame() in _twin_box_dispatch(), I placed twin_window_frame() in twin.h. Therefore, I make this modification. However, I later changed the location where twin_window_frame() is called to achieve the same effect, so it no longer needs to be called in box.c. It was my mistake for forgetting to change it back.

[weihsinyeh]

At the beginning, is it reasonable for there to be no active window displayed?

[ndsl7109256]

At the beginning, is it reasonable for there to be no active window displayed?

On macOS, there is always an active window at the top, but I'm not sure how it performs on other platforms. Besides, I noticed that if I click the top window first, it doesn't get activated.

2025-02-01.2.44.09.mov

[huaxinliao]

Here's the output of fbdev from commit e80e45e on the Raspberry Pi 3B.

20250202_fbdev.mp4

[jserv]

Thank @weihsinyeh for contributing!