🚧 Basic tiling window creation

Only supports creation of windows with horizontal splitting, and not
removal of windows.

CMakeLists.txt

@@ -1,7 +1,9 @@
-cmake_minimum_required(VERSION 3.20)
+cmake_minimum_required(VERSION 3.21)
 
 project(aswm)
 
+set(CMAKE_C_STANDARD 23)
+
 find_package(X11 REQUIRED)
 
 set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -fsanitize=address")
@@ -9,6 +11,7 @@ set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -fsanitize=address")
 add_executable(aswm
 	src/aswm/main.c
 	src/aswm/aswm.c
+	src/aswm/mapper/mapper.c
 	src/aswm/event_handlers/create.c
 	src/aswm/event_handlers/configure.c
 	src/aswm/event_handlers/reparent.c

include/aswm/aswm.h

@@ -1,11 +1,16 @@
-#include <X11/Xlib.h>
+#ifndef ASWM
+#define ASWM
+
+#include "aswm/mapper/mapper.h"
 
 typedef struct {
 	Display *display;
-	Window root;
-} aswm;
+	Window root_window;
+	AswmTile* root_tile;
+} Aswm;
 
-void AswmOpen();
-void AswmEventLoop();
-void AswmClose();
+void aswm_open();
+void aswm_event_loop();
+void aswm_close();
 
+#endif

include/aswm/event_handlers/map.h

@@ -1,3 +1,4 @@
 #include <X11/Xlib.h>
+#include "aswm/aswm.h"
 
-void OnMapRequest(Window root, const XMapRequestEvent* e);
+void OnMapRequest(Aswm* aswm, const XMapRequestEvent* e);

include/aswm/mapper/mapper.h

@@ -0,0 +1,24 @@
+#ifndef ASWM_MAPPER
+#define ASWM_MAPPER
+
+#include <X11/Xlib.h>
+
+struct AswmTile;
+
+typedef struct AswmTile {
+	int x, y;
+	int width, height;
+	bool free;
+	Display* display;
+	Window window;
+	bool has_children;
+	struct AswmTile* children[2];
+} AswmTile;
+
+AswmTile* aswm_alloc_tile();
+AswmTile* aswm_alloc_root_tile(Display* display, Window window);
+void aswm_free_tile(AswmTile* tile);
+
+AswmTile* aswm_map_new_window(Display* display, Window window, AswmTile* tile);
+
+#endif

src/aswm/aswm.c

@@ -1,3 +1,4 @@
+#include <stdlib.h>
 #include "aswm/aswm.h"
 #include "aswm/event_handlers/create.h"
 #include "aswm/event_handlers/configure.h"
@@ -5,17 +6,22 @@
 #include "aswm/event_handlers/reparent.h"
 #include "aswm/event_handlers/destroy.h"
 
-aswm _aswm;
+Aswm _aswm;
 
-void AswmOpen() {
+void aswm_open() {
 	_aswm.display = XOpenDisplay(NULL);
-	_aswm.root = DefaultRootWindow(_aswm.display);
+	_aswm.root_window = DefaultRootWindow(_aswm.display);
 
-	XSelectInput(_aswm.display, _aswm.root, SubstructureRedirectMask | SubstructureNotifyMask);
+
+	_aswm.root_tile = aswm_alloc_root_tile(_aswm.display, _aswm.root_window);
+
+	XSelectInput(_aswm.display, _aswm.root_window, SubstructureRedirectMask | SubstructureNotifyMask);
 	XSync(_aswm.display, 0);
+
+	atexit(aswm_close);
 }
 
-void AswmEventLoop() {
+void aswm_event_loop() {
 	for (;;) {
 		XEvent e;
 		XNextEvent(_aswm.display, &e);
@@ -28,7 +34,7 @@ void AswmEventLoop() {
 				OnConfigureRequest(&e.xconfigurerequest);
 				break;
 			case MapRequest:
-				OnMapRequest(_aswm.root, &e.xmaprequest);
+				OnMapRequest(&_aswm, &e.xmaprequest);
 				break;
 			case DestroyNotify:
 				OnDestroyNotify(&e.xdestroywindow);
@@ -43,6 +49,7 @@ void AswmEventLoop() {
 	}
 }
 
-void AswmClose() {
+void aswm_close() {
+	aswm_free_tile(_aswm.root_tile);
 	XCloseDisplay(_aswm.display);
 }

src/aswm/event_handlers/map.c

@@ -2,7 +2,7 @@
 #include <stdio.h>
 #include <X11/Xutil.h>
 
-void OnMapRequest(Window root, const XMapRequestEvent* e) {
+void OnMapRequest(Aswm* aswm, const XMapRequestEvent* e) {
 	printf("XMapRequestEvent %lu\n", e->window);
 
 	{
@@ -20,19 +20,6 @@ void OnMapRequest(Window root, const XMapRequestEvent* e) {
 	int full_width = XDisplayWidth(e->display, screen_number);
 	int full_height = XDisplayWidth(e->display, screen_number);
 
-	// Automatically reconfigure position and size of the window
-	XWindowChanges changes;
-	changes.x = 0;
-	changes.y = 0;
-	changes.width = full_width;
-	changes.height = full_height;
-
-	printf("\tx = %i\n", changes.x);
-	printf("\ty = %i\n", changes.y);
-	printf("\tw = %i\n", changes.width);
-	printf("\th = %i\n", changes.height);
-
-	XConfigureWindow(e->display, e->window, CWX | CWY | CWWidth | CWHeight, &changes);
-
+	aswm_map_new_window(e->display, e->window, aswm->root_tile);
 	XMapWindow(e->display, e->window);
 }

src/aswm/main.c

@@ -1,7 +1,7 @@
 #include "aswm/aswm.h"
 
 int main(int argc, char** argv) {
-	AswmOpen();
-	AswmEventLoop();
-	AswmClose();
+	aswm_open();
+	aswm_event_loop();
+	aswm_close();
 }

src/aswm/mapper/mapper.c

@@ -0,0 +1,85 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "aswm/mapper/mapper.h"
+
+AswmTile* aswm_alloc_tile() {
+	AswmTile* tile = malloc(sizeof(AswmTile));
+	for(int i = 0; i < 2; i++)
+		tile->children[i] = nullptr;
+	return tile;
+}
+
+AswmTile* aswm_alloc_root_tile(Display* display, Window window) {
+	int screen_number = XDefaultScreen(display);
+	AswmTile* tile = aswm_alloc_tile();
+
+	tile->has_children = false;
+	tile->x = 0;
+	tile->y = 0;
+	tile->free = true;
+	tile->width = XDisplayWidth(display, screen_number);
+	tile->height = XDisplayHeight(display, screen_number);
+
+	return tile;
+}
+
+void aswm_free_tile(AswmTile* tile) {
+	for(int i = 0; i < 2; i++)
+		aswm_free_tile(tile->children[i]);
+	if(tile != nullptr)
+		free(tile);
+}
+
+/**
+ * Returns the free tile built in the split process.
+ */
+AswmTile* h_split(AswmTile* tile);
+
+AswmTile* aswm_map_new_window(Display* display, Window window, AswmTile* tile) {
+	if(tile->has_children) {
+		// The tile is necessarily considered occupied
+		return aswm_map_new_window(display, window, tile->children[1]);
+	}
+	if(tile->free) {
+		// Leef of the tile tree, the window can be inserted there
+		tile->free = false;
+		tile->display = display;
+		tile->window = window;
+
+		// Automatically reconfigure position and size of the window
+		XWindowChanges changes;
+		changes.x = tile->x;
+		changes.y = tile->y;
+		changes.width = tile->width;
+		changes.height = tile->height;
+
+		printf("\tx = %i\n", changes.x);
+		printf("\ty = %i\n", changes.y);
+		printf("\tw = %i\n", changes.width);
+		printf("\th = %i\n", changes.height);
+
+		XConfigureWindow(display, window, CWX | CWY | CWWidth | CWHeight, &changes);
+		return tile;
+	}
+	// Leef of tile tree, but occupied. Split the tile and map the window to the
+	// new tile.
+	return aswm_map_new_window(display, window, h_split(tile));
+}
+
+AswmTile* h_split(AswmTile* tile) {
+	tile->has_children = true;
+	for(int i = 0; i < 2; i++) {
+		tile->children[i] = aswm_alloc_tile();
+		tile->children[i]->has_children = false;
+		tile->children[i]->free = true;
+		tile->children[i]->x = tile->x;
+		tile->children[i]->width = tile->width;
+		tile->children[i]->height = tile->height / 2;
+	}
+	tile->children[0]->y = tile->y;
+	tile->children[1]->y = tile->y + tile->children[0]->height;
+
+	aswm_map_new_window(tile->display, tile->window, tile->children[0]);
+
+	return tile->children[1];
+}