windowmaker-wl/WINGs/wview_wl.c

/*
 * wview_wl.c - Wayland view backend for WINGs
 *
 * Views are logical layout containers in Wayland mode.
 * No X11 dependencies. Rendering is handled by frame_paint (pixman buffers).
 */

#include "WINGsP.h"
#include <pixman.h>

/* Synthetic window IDs for Wayland views (distinct from frame buffer IDs) */
#define WL_VIEW_ID_BASE  0x20000000
static unsigned int wl_view_next_id = WL_VIEW_ID_BASE;

/* Callback set by WM backend to commit frame_buf after paint */
void (*W_ViewCommitBackingFn)(unsigned long id) = NULL;
void (*W_ViewDestroyBackingFn)(unsigned long id) = NULL;

/* Clipboard hooks set by WM backend for cross-client clipboard */
void (*W_ClipboardStoreFn)(const char *text, int len) = NULL;
char *(*W_ClipboardFetchFn)(int *len_out) = NULL;

extern void wl_view_destroy_backing_impl(unsigned long id);

/* Simple view lookup table (ID → W_View*) */
#define VIEW_TABLE_SIZE 256
static struct { Window id; W_View *view; void *backing; } view_table[VIEW_TABLE_SIZE];

static void view_table_put(Window id, W_View *view)
{
	unsigned idx = ((unsigned)id) % VIEW_TABLE_SIZE;
	for (int i = 0; i < VIEW_TABLE_SIZE; i++) {
		unsigned slot = (idx + i) % VIEW_TABLE_SIZE;
		if (view_table[slot].id == 0 || view_table[slot].id == id) {
			view_table[slot].id = id;
			view_table[slot].view = view;
			return;
		}
	}
}

W_View *W_GetViewForWindow(Window id)
{
	unsigned idx = ((unsigned)id) % VIEW_TABLE_SIZE;
	for (int i = 0; i < VIEW_TABLE_SIZE; i++) {
		unsigned slot = (idx + i) % VIEW_TABLE_SIZE;
		if (view_table[slot].id == id)
			return view_table[slot].view;
		if (view_table[slot].id == 0) {
			//wwarning("W_GetViewForWindow: id=0x%lx NOT FOUND (slot %u empty)", (unsigned long)id, slot);
			return NULL;
		}
	}
	return NULL;
}

/* Get/set backing pixman image for a view ID */
void *W_GetViewBacking(Window id)
{
	unsigned idx = ((unsigned)id) % VIEW_TABLE_SIZE;
	for (int i = 0; i < VIEW_TABLE_SIZE; i++) {
		unsigned slot = (idx + i) % VIEW_TABLE_SIZE;
		if (view_table[slot].id == id)
			return view_table[slot].backing;
		if (view_table[slot].id == 0)
			return NULL;
	}
	return NULL;
}

void W_SetViewBacking(Window id, void *img)
{
	unsigned idx = ((unsigned)id) % VIEW_TABLE_SIZE;
	for (int i = 0; i < VIEW_TABLE_SIZE; i++) {
		unsigned slot = (idx + i) % VIEW_TABLE_SIZE;
		if (view_table[slot].id == id) {
			view_table[slot].backing = img;
			return;
		}
		if (view_table[slot].id == 0)
			return;
	}
}

static void view_table_remove(Window id)
{
	unsigned idx = ((unsigned)id) % VIEW_TABLE_SIZE;
	for (int i = 0; i < VIEW_TABLE_SIZE; i++) {
		unsigned slot = (idx + i) % VIEW_TABLE_SIZE;
		if (view_table[slot].id == id) {
			view_table[slot].id = 0;
			view_table[slot].view = NULL;
			view_table[slot].backing = NULL;
			return;
		}
		if (view_table[slot].id == 0)
			return;
	}
}

Bool W_IsValidView(W_View *view)
{
    if (!view) return False;
    unsigned idx = ((unsigned)view->window) % VIEW_TABLE_SIZE;
    for (int i = 0; i < VIEW_TABLE_SIZE; i++) {
        unsigned slot = (idx + i) % VIEW_TABLE_SIZE;
        if (view_table[slot].view == view)
            return True;
        if (view_table[slot].id == 0)
            return False;
    }
    return False;
}

/*
 * W_RegisterBacking - register a pixman_image_t backing for any synthetic
 * window ID (WINGs views OR WM frame_buf windows).  Used by wl_backend.c so
 * that WMDrawString() can resolve a WM window ID to a pixman_image_t when
 * drawing text into frame_buf images (e.g. miniwindow title).
 */
void W_RegisterBacking(Window id, void *img)
{
	view_table_put(id, NULL);
	W_SetViewBacking(id, img);
}

/* W_UnregisterBacking - remove a backing registration (on frame_buf destroy). */
void W_UnregisterBacking(Window id)
{
	view_table_remove(id);
}

static void *wl_screen_init(W_Screen *scr)
{
	(void)scr;
	return scr; /* use scr as token */
}

static void wl_screen_fini(void *vctx)
{
	(void)vctx;
}

static void wl_create_root(void *vctx, W_View *view)
{
	(void)vctx;

	view->window = (Window)wl_view_next_id++;
	view_table_put(view->window, view);
	/* Default screen size — the WM backend will update this */
	view->size.width = 1920;
	view->size.height = 1080;
}

static void wl_realize(void *vctx, W_View *view)
{
	(void)vctx;

	/* Assign a synthetic ID so W_DispatchMessage doesn't skip this view */
	view->window = (Window)wl_view_next_id++;
	view_table_put(view->window, view);

	/* Allocate a backing pixman image for this view */
	int w = view->size.width > 0 ? view->size.width : 1;
	int h = view->size.height > 0 ? view->size.height : 1;
	pixman_image_t *img = pixman_image_create_bits(PIXMAN_a8r8g8b8, w, h, NULL, 0);
	W_SetViewBacking(view->window, img);
}

static void wl_redisplay(void *vctx, W_View *view);

static void wl_unmap(void *vctx, W_View *view)
{
	(void)vctx;
	view->flags.mapped = 0;
	if (view->parent && view->parent->flags.mapped)
		wl_redisplay(vctx, view->parent);
}

static void wl_unmap_subviews(void *vctx, W_View *view)
{
	W_View *child = view->childrenList;
	while (child) {
		child->flags.mapped = 0;
		if (child->childrenList)
			wl_unmap_subviews(vctx, child);
		child = child->nextSister;
	}
}

static void wl_raise(void *vctx, W_View *view)
{
	(void)vctx;
	W_View *parent = view->parent;
	if (!parent) return;

	/* Remove from list */
	if (parent->childrenList == view) {
		parent->childrenList = view->nextSister;
	} else {
		W_View *prev = parent->childrenList;
		while (prev && prev->nextSister != view)
			prev = prev->nextSister;
		if (prev)
			prev->nextSister = view->nextSister;
	}

	/* Append to end (drawn last = on top) */
	view->nextSister = NULL;
	if (!parent->childrenList) {
		parent->childrenList = view;
	} else {
		W_View *last = parent->childrenList;
		while (last->nextSister)
			last = last->nextSister;
		last->nextSister = view;
	}

	if (parent->flags.mapped)
		wl_redisplay(vctx, parent);
}

static void wl_lower(void *vctx, W_View *view)
{
	(void)vctx;
	W_View *parent = view->parent;
	if (!parent) return;

	/* Remove from list */
	if (parent->childrenList == view) {
		parent->childrenList = view->nextSister;
	} else {
		W_View *prev = parent->childrenList;
		while (prev && prev->nextSister != view)
			prev = prev->nextSister;
		if (prev)
			prev->nextSister = view->nextSister;
	}

	/* Prepend to front (drawn first = on bottom) */
	view->nextSister = parent->childrenList;
	parent->childrenList = view;

	if (parent->flags.mapped)
		wl_redisplay(vctx, parent);
}

static void wl_map_subviews(void *vctx, W_View *view);

static void wl_map(void *vctx, W_View *view)
{
	(void)vctx;
	view->flags.mapped = 1;
	if (view->flags.topLevel && view->flags.realized) {
		wl_redisplay(vctx, view);
		wl_map_subviews(vctx, view);
		/* Re-composite top-level after children have drawn into it */
		if (view->parent) {
			pixman_image_t *src = (pixman_image_t *)W_GetViewBacking(view->window);
			pixman_image_t *dst = (pixman_image_t *)W_GetViewBacking(view->parent->window);
			if (src && dst) {
				pixman_image_composite32(PIXMAN_OP_OVER, src, NULL, dst,
					0, 0, 0, 0,
					view->pos.x, view->pos.y,
					view->size.width, view->size.height);
			}
		}
	}
}

static void wl_map_subviews(void *vctx, W_View *view)
{
	W_View *child = view->childrenList;
	while (child) {
		if (child->flags.realized) {
			child->flags.mapped = 1;
			wl_redisplay(vctx, child);
			/* Recurse into grandchildren */
			if (child->childrenList)
				wl_map_subviews(vctx, child);
			/* Re-composite child after grandchildren have drawn into it */
			pixman_image_t *src = (pixman_image_t *)W_GetViewBacking(child->window);
			pixman_image_t *dst = (pixman_image_t *)W_GetViewBacking(view->window);
			if (src && dst) {
				pixman_image_composite32(PIXMAN_OP_OVER, src, NULL, dst,
					0, 0, 0, 0,
					child->pos.x, child->pos.y,
					child->size.width, child->size.height);
			}
		} else {
			if (child->childrenList)
				wl_map_subviews(vctx, child);
		}
		child = child->nextSister;
	}
}

static void wl_move(void *vctx, W_View *view, int x, int y)
{
	(void)vctx;
	view->pos.x = x;
	view->pos.y = y;
	if (view->parent && view->flags.mapped)
		wl_redisplay(vctx, view->parent);
}

static void wl_resize(void *vctx, W_View *view, unsigned int w, unsigned int h)
{
	(void)vctx;
	view->size.width = w;
	view->size.height = h;

	/* Reallocate backing pixman buffer */
	pixman_image_t *old = (pixman_image_t *)W_GetViewBacking(view->window);
	if (old)
		pixman_image_unref(old);
	int bw = w > 0 ? (int)w : 1;
	int bh = h > 0 ? (int)h : 1;
	pixman_image_t *img = pixman_image_create_bits(PIXMAN_a8r8g8b8, bw, bh, NULL, 0);
	W_SetViewBacking(view->window, img);

	if (view->flags.mapped)
		wl_redisplay(vctx, view);
}

static void wl_reparent(void *vctx, W_View *view, W_View *newParent, int x, int y)
{
	(void)vctx;
	W_View *oldParent = view->parent;

	/* Remove from old parent's children list */
	if (oldParent) {
		if (oldParent->childrenList == view) {
			oldParent->childrenList = view->nextSister;
		} else {
			W_View *prev = oldParent->childrenList;
			while (prev && prev->nextSister != view)
				prev = prev->nextSister;
			if (prev)
				prev->nextSister = view->nextSister;
		}
	}

	/* Insert into new parent's children list */
	view->nextSister = newParent->childrenList;
	newParent->childrenList = view;
	view->parent = newParent;
	view->pos.x = x;
	view->pos.y = y;

	if (oldParent && oldParent->flags.mapped)
		wl_redisplay(vctx, oldParent);
	if (view->flags.mapped)
		wl_redisplay(vctx, newParent);
}

static void wl_destroy(void *vctx, W_View *view)
{
	(void)vctx;
	W_WL_InvalidateView(view->screen, view);
	if (view->flags.topLevel && W_ViewDestroyBackingFn)
		W_ViewDestroyBackingFn((unsigned long)view->window);
}

static void wl_set_background_color(void *vctx, W_View *view, WMColor *color)
{
	(void)vctx;
	(void)view;
	(void)color;
	/* Background is handled by pixman rendering in frame_paint */
}

static void wl_set_cursor(void *vctx, W_View *view, Cursor cursor)
{
	(void)vctx;
	(void)view;
	(void)cursor;
	/* Cursor is managed by wlroots seat */
}

static void wl_redisplay(void *vctx, W_View *view)
{
	WMEvent ev;

	(void)vctx;

	if (!view->flags.mapped)
		return;

	/* Fill background color */
	pixman_image_t *backing = (pixman_image_t *)W_GetViewBacking(view->window);
	if (backing && view->backColor) {
		pixman_color_t bg;
		bg.red   = view->backColor->color.red;
		bg.green = view->backColor->color.green;
		bg.blue  = view->backColor->color.blue;
		bg.alpha = view->backColor->alpha ? view->backColor->alpha : 0xFFFF;
		pixman_image_fill_rectangles(PIXMAN_OP_SRC, backing, &bg,
			1, &(pixman_rectangle16_t){0, 0, view->size.width, view->size.height});
	} else if (backing) {
		/* Default: light grey background */
		pixman_color_t bg = {0xAAAA, 0xAAAA, 0xAAAA, 0xFFFF};
		pixman_image_fill_rectangles(PIXMAN_OP_SRC, backing, &bg,
			1, &(pixman_rectangle16_t){0, 0, view->size.width, view->size.height});
	}

	memset(&ev, 0, sizeof(ev));
	ev.type = WME_EXPOSE;
	ev.window = (WNativeWindow)view->window;
	ev.u.expose.window = (WNativeWindow)view->window;
	ev.u.expose.count = 0;
	ev._x11_raw = NULL;
	ev._view_target = view;

	WMHandleEvent(&ev);

	/* Composite this view's backing into its parent's backing */
	if (view->parent) {
		pixman_image_t *src = (pixman_image_t *)W_GetViewBacking(view->window);
		pixman_image_t *dst = (pixman_image_t *)W_GetViewBacking(view->parent->window);
		if (src && dst) {
			pixman_image_composite32(PIXMAN_OP_OVER, src, NULL, dst,
				0, 0, 0, 0,
				view->pos.x, view->pos.y,
				view->size.width, view->size.height);
		}
	}

	/* Notify WM backend to commit the top-level view's backing buffer */
	/* Walk up to find the top-level view */
	W_View *top = view;
	while (top->parent && !top->flags.topLevel)
		top = top->parent;

	extern void (*W_ViewCommitBackingFn)(unsigned long id);
	if (W_ViewCommitBackingFn)
		W_ViewCommitBackingFn((unsigned long)top->window);
}

/* Find the deepest child view at (x, y) relative to the given view. */
W_View *W_FindViewAtPoint(W_View *parent, int x, int y)
{
	if (!parent) return NULL;
	W_View *child = parent->childrenList;
	while (child) {
		if (child->flags.mapped && child->flags.realized &&
		    x >= child->pos.x && x < child->pos.x + child->size.width &&
		    y >= child->pos.y && y < child->pos.y + child->size.height) {
			/* Recurse into this child with local coordinates */
			W_View *deeper = W_FindViewAtPoint(child,
				x - child->pos.x, y - child->pos.y);
			return deeper ? deeper : child;
		}
		child = child->nextSister;
	}
	return NULL;
}

static WMPoint wl_get_screen_position(void *vctx, W_View *view)
{
	W_Screen *scr = (W_Screen *)vctx;
	int x = 0, y = 0;
	W_View *v;

	/* Walk up the view tree accumulating positions */
	for (v = view; v && v != scr->rootView; v = v->parent) {
		x += v->pos.x;
		y += v->pos.y;
	}

	return wmkpoint(x, y);
}

static Bool wl_selection_acquire(void *vctx, W_View *view, Atom selection, Time timestamp)
{
	(void)vctx; (void)view; (void)selection; (void)timestamp;
	/* TODO: implement via wl_data_device */
	return True;
}

static void wl_selection_release(void *vctx, W_View *view, Atom selection)
{
	(void)vctx; (void)view; (void)selection;
}

static char *wl_selection_fetch(void *vctx, Atom selection, int *len_out)
{
	(void)vctx; (void)selection;
	/* Use the clipboard fetch path (reads from seat selection via pipe) */
	if (W_ClipboardFetchFn)
		return W_ClipboardFetchFn(len_out);
	if (len_out)
		*len_out = 0;
	return NULL;
}

static char *wl_clipboard_buf = NULL;
static int wl_clipboard_len = 0;

static void wl_clipboard_store(void *vctx, const char *text, int len)
{
	(void)vctx;
	if (wl_clipboard_buf)
		wfree(wl_clipboard_buf);
	if (text && len > 0) {
		wl_clipboard_buf = wmalloc(len + 1);
		memcpy(wl_clipboard_buf, text, len);
		wl_clipboard_buf[len] = '\0';
		wl_clipboard_len = len;
		if (W_ClipboardStoreFn)
			W_ClipboardStoreFn(text, len);
	} else {
		wl_clipboard_buf = NULL;
		wl_clipboard_len = 0;
	}
}

static char *wl_clipboard_fetch(void *vctx, int *len_out)
{
	(void)vctx;
	/* Try seat selection first (cross-client paste) */
	if (W_ClipboardFetchFn) {
		int n = 0;
		char *text = W_ClipboardFetchFn(&n);
		if (text) {
			if (len_out)
				*len_out = n;
			return text;
		}
	}
	/* Fall back to internal buffer */
	if (wl_clipboard_buf && wl_clipboard_len > 0) {
		char *copy = wmalloc(wl_clipboard_len + 1);
		memcpy(copy, wl_clipboard_buf, wl_clipboard_len);
		copy[wl_clipboard_len] = '\0';
		if (len_out)
			*len_out = wl_clipboard_len;
		return copy;
	}
	if (len_out)
		*len_out = 0;
	return NULL;
}

static void wl_text_init(void *vctx, W_View *view, void *stipple_gc_out)
{
	(void)vctx; (void)view; (void)stipple_gc_out;
}

static void wl_balloon_draw(void *vctx, W_View *view, int x, int y,
                            int w, int h, const char *text)
{
	(void)vctx; (void)view; (void)x; (void)y; (void)w; (void)h; (void)text;
}

static void wl_drag_begin(void *vctx, W_View *view, WMEvent *event)
{
	W_Screen *scr = (W_Screen *)vctx;
	if (!view->dragSourceProcs || event->type != WME_BUTTON_PRESS)
		return;

	/* Wait for motion to confirm drag */
	WMEvent ev;
	WMMaskEvent(scr, ButtonMotionMask | ButtonReleaseMask, &ev);
	if (ev.type != WME_MOTION)
		return;

	if (view->dragSourceProcs->beganDrag) {
		WMPoint pt = wmkpoint(ev.u.motion.x_root, ev.u.motion.y_root);
		view->dragSourceProcs->beganDrag(view, &pt);
	}

	/* Drag loop */
	W_View *destView = NULL;
	Bool deposited = False;
	int done = 0;

	while (!done) {
		WMMaskEvent(scr, ButtonMotionMask | ButtonReleaseMask, &ev);
		switch (ev.type) {
		case WME_MOTION:
			/* Find view under cursor */
			{
				W_View *top = scr->rootView;
				int mx = ev.u.motion.x_root;
				int my = ev.u.motion.y_root;
				destView = W_FindViewAtPoint(top, mx, my);
			}
			break;

		case WME_BUTTON_RELEASE:
			if (destView && destView->dragDestinationProcs &&
			    destView->droppableTypes && view->dragSourceProcs->dropDataTypes) {
				WMArray *types = view->dragSourceProcs->dropDataTypes(view);
				WMArray *dropData = WMCreateArray(WMGetArrayItemCount(types));
				int i;
				for (i = 0; i < WMGetArrayItemCount(types); i++) {
					char *type = WMGetFromArray(types, i);
					WMData *data = view->dragSourceProcs->fetchDragData(view, type);
					if (data)
						WMAddToArray(dropData, data);
				}
				if (WMGetArrayItemCount(dropData) > 0 &&
				    destView->dragDestinationProcs->performDragOperation) {
					WMPoint pt = wmkpoint(ev.u.button.x_root, ev.u.button.y_root);
					destView->dragDestinationProcs->performDragOperation(
						destView, dropData, NULL, &pt);
					deposited = True;
				}
				WMFreeArray(dropData);
			}
			done = 1;
			break;
		}
	}

	if (view->dragSourceProcs->endedDrag) {
		WMPoint pt = wmkpoint(ev.u.button.x_root, ev.u.button.y_root);
		view->dragSourceProcs->endedDrag(view, &pt, deposited);
	}
}

static void wl_flush(void *vctx)
{
	(void)vctx;
}

static void wl_window_set_title(void *vctx, W_View *view, const char *title)
{
	(void)vctx; (void)view; (void)title;
}

static void wl_window_set_icon_title(void *vctx, W_View *view, const char *title)
{
	(void)vctx; (void)view; (void)title;
}

static void wl_window_set_icon_image(void *vctx, W_View *view, RImage *image)
{
	(void)vctx; (void)view; (void)image;
}

static void wl_window_realize(void *vctx, W_View *view, const char *name,
			     const char *class, W_View *owner)
{
	(void)vctx; (void)view; (void)name; (void)class; (void)owner;
}

static void wl_window_set_geometry(void *vctx, W_View *view)
{
	(void)vctx; (void)view;
}

static void wl_window_withdraw(void *vctx, W_View *view)
{
	(void)vctx; (void)view;
}

const W_ViewBackend W_ViewBackendWL = {
	.screen_init          = wl_screen_init,
	.screen_fini          = wl_screen_fini,
	.create_root          = wl_create_root,
	.realize              = wl_realize,
	.map                  = wl_map,
	.unmap                = wl_unmap,
	.map_subviews         = wl_map_subviews,
	.unmap_subviews       = wl_unmap_subviews,
	.move                 = wl_move,
	.resize               = wl_resize,
	.raise                = wl_raise,
	.lower                = wl_lower,
	.reparent             = wl_reparent,
	.destroy              = wl_destroy,
	.set_background_color = wl_set_background_color,
	.set_cursor           = wl_set_cursor,
	.redisplay            = wl_redisplay,
	.get_screen_position  = wl_get_screen_position,
	.selection_acquire    = wl_selection_acquire,
	.selection_release    = wl_selection_release,
	.selection_request    = NULL,
	.selection_fetch      = wl_selection_fetch,
	.platform_init        = NULL,
	.flush                = wl_flush,
	.clipboard_store      = wl_clipboard_store,
	.clipboard_fetch      = wl_clipboard_fetch,
	.drag_begin           = wl_drag_begin,
	.window_set_title     = wl_window_set_title,
	.window_set_icon_title = wl_window_set_icon_title,
	.window_set_icon_image = wl_window_set_icon_image,
	.window_realize       = wl_window_realize,
	.window_set_geometry  = wl_window_set_geometry,
	.window_withdraw      = wl_window_withdraw,
	.pointer_grab         = NULL,
	.pointer_ungrab       = NULL,
	.bell                 = NULL,
	.balloon_draw         = wl_balloon_draw,
	.text_init            = wl_text_init,
	.xor_fill_rect        = NULL,
	.magnify_callback     = NULL,
};