1 files changed, 496 insertions, 0 deletions
diff --git a/examples/dte/frame.c b/examples/dte/frame.c
new file mode 100644
index 0000000..c06b2d8
--- /dev/null
+++ b/examples/dte/frame.c
@@ -0,0 +1,496 @@
+#include "frame.h"
+#include "editor.h"
+#include "util/debug.h"
+#include "util/xmalloc.h"
+#include "window.h"
+
+enum {
+    WINDOW_MIN_WIDTH = 8,
+    WINDOW_MIN_HEIGHT = 3,
+};
+
+static void sanity_check_frame(const Frame *frame)
+{
+    bool has_window = !!frame->window;
+    bool has_frames = frame->frames.count > 0;
+    if (has_window == has_frames) {
+        BUG("frames must contain a window or subframe(s), but never both");
+    }
+    BUG_ON(has_window && frame != frame->window->frame);
+}
+
+static int get_min_w(const Frame *frame)
+{
+    if (frame->window) {
+        return WINDOW_MIN_WIDTH;
+    }
+
+    const PointerArray *subframes = &frame->frames;
+    const size_t count = subframes->count;
+    if (!frame->vertical) {
+        int w = count - 1; // Separators
+        for (size_t i = 0; i < count; i++) {
+            w += get_min_w(subframes->ptrs[i]);
+        }
+        return w;
+    }
+
+    int max = 0;
+    for (size_t i = 0; i < count; i++) {
+        int w = get_min_w(subframes->ptrs[i]);
+        max = MAX(w, max);
+    }
+    return max;
+}
+
+static int get_min_h(const Frame *frame)
+{
+    if (frame->window) {
+        return WINDOW_MIN_HEIGHT;
+    }
+
+    const PointerArray *subframes = &frame->frames;
+    const size_t count = subframes->count;
+    if (frame->vertical) {
+        int h = 0;
+        for (size_t i = 0; i < count; i++) {
+            h += get_min_h(subframes->ptrs[i]);
+        }
+        return h;
+    }
+
+    int max = 0;
+    for (size_t i = 0; i < count; i++) {
+        int h = get_min_h(subframes->ptrs[i]);
+        max = MAX(h, max);
+    }
+    return max;
+}
+
+static int get_min(const Frame *frame)
+{
+    return frame->parent->vertical ? get_min_h(frame) : get_min_w(frame);
+}
+
+static int get_size(const Frame *frame)
+{
+    return frame->parent->vertical ? frame->h : frame->w;
+}
+
+static int get_container_size(const Frame *frame)
+{
+    return frame->vertical ? frame->h : frame->w;
+}
+
+static void set_size(Frame *frame, int size)
+{
+    bool vertical = frame->parent->vertical;
+    int w = vertical ? frame->parent->w : size;
+    int h = vertical ? size : frame->parent->h;
+    set_frame_size(frame, w, h);
+}
+
+static void divide_equally(const Frame *frame)
+{
+    size_t count = frame->frames.count;
+    BUG_ON(count == 0);
+
+    int *min = xnew(int, count);
+    for (size_t i = 0; i < count; i++) {
+        min[i] = get_min(frame->frames.ptrs[i]);
+    }
+
+    int *size = xnew0(int, count);
+    int s = get_container_size(frame);
+    int q, r, used;
+    size_t n = count;
+
+    // Consume q and r as equally as possible
+    do {
+        used = 0;
+        q = s / n;
+        r = s % n;
+        for (size_t i = 0; i < count; i++) {
+            if (size[i] == 0 && min[i] > q) {
+                size[i] = min[i];
+                used += min[i];
+                n--;
+            }
+        }
+        s -= used;
+    } while (used && n > 0);
+
+    for (size_t i = 0; i < count; i++) {
+        Frame *c = frame->frames.ptrs[i];
+        if (size[i] == 0) {
+            size[i] = q + (r-- > 0);
+        }
+        set_size(c, size[i]);
+    }
+
+    free(size);
+    free(min);
+}
+
+static void fix_size(const Frame *frame)
+{
+    size_t count = frame->frames.count;
+    int *size = xnew(int, count);
+    int *min = xnew(int, count);
+    int total = 0;
+    for (size_t i = 0; i < count; i++) {
+        const Frame *c = frame->frames.ptrs[i];
+        min[i] = get_min(c);
+        size[i] = MAX(get_size(c), min[i]);
+        total += size[i];
+    }
+
+    int s = get_container_size(frame);
+    if (total > s) {
+        int n = total - s;
+        for (ssize_t i = count - 1; n > 0 && i >= 0; i--) {
+            int new_size = MAX(size[i] - n, min[i]);
+            n -= size[i] - new_size;
+            size[i] = new_size;
+        }
+    } else {
+        size[count - 1] += s - total;
+    }
+
+    for (size_t i = 0; i < count; i++) {
+        set_size(frame->frames.ptrs[i], size[i]);
+    }
+
+    free(size);
+    free(min);
+}
+
+static void add_to_sibling_size(Frame *frame, int count)
+{
+    const Frame *parent = frame->parent;
+    size_t idx = ptr_array_idx(&parent->frames, frame);
+    BUG_ON(idx >= parent->frames.count);
+    if (idx == parent->frames.count - 1) {
+        frame = parent->frames.ptrs[idx - 1];
+    } else {
+        frame = parent->frames.ptrs[idx + 1];
+    }
+    set_size(frame, get_size(frame) + count);
+}
+
+static int sub(Frame *frame, int count)
+{
+    int min = get_min(frame);
+    int old = get_size(frame);
+    int new = MAX(min, old - count);
+    if (new != old) {
+        set_size(frame, new);
+    }
+    return count - (old - new);
+}
+
+static void subtract_from_sibling_size(const Frame *frame, int count)
+{
+    const Frame *parent = frame->parent;
+    size_t idx = ptr_array_idx(&parent->frames, frame);
+    BUG_ON(idx >= parent->frames.count);
+
+    for (size_t i = idx + 1, n = parent->frames.count; i < n; i++) {
+        count = sub(parent->frames.ptrs[i], count);
+        if (count == 0) {
+            return;
+        }
+    }
+
+    for (size_t i = idx; i > 0; i--) {
+        count = sub(parent->frames.ptrs[i - 1], count);
+        if (count == 0) {
+            return;
+        }
+    }
+}
+
+static void resize_to(Frame *frame, int size)
+{
+    const Frame *parent = frame->parent;
+    int total = parent->vertical ? parent->h : parent->w;
+    int count = parent->frames.count;
+    int min = get_min(frame);
+    int max = total - (count - 1) * min;
+    max = MAX(min, max);
+    size = CLAMP(size, min, max);
+
+    int change = size - get_size(frame);
+    if (change == 0) {
+        return;
+    }
+
+    set_size(frame, size);
+    if (change < 0) {
+        add_to_sibling_size(frame, -change);
+    } else {
+        subtract_from_sibling_size(frame, change);
+    }
+}
+
+static bool rightmost_frame(const Frame *frame)
+{
+    const Frame *parent = frame->parent;
+    if (!parent) {
+        return true;
+    }
+    if (!parent->vertical) {
+        if (frame != parent->frames.ptrs[parent->frames.count - 1]) {
+            return false;
+        }
+    }
+    return rightmost_frame(parent);
+}
+
+static Frame *new_frame(void)
+{
+    Frame *frame = xnew0(Frame, 1);
+    frame->equal_size = true;
+    return frame;
+}
+
+static Frame *add_frame(Frame *parent, Window *window, size_t idx)
+{
+    Frame *frame = new_frame();
+    frame->parent = parent;
+    frame->window = window;
+    window->frame = frame;
+    if (parent) {
+        BUG_ON(idx > parent->frames.count);
+        ptr_array_insert(&parent->frames, frame, idx);
+        parent->window = NULL;
+    }
+    return frame;
+}
+
+Frame *new_root_frame(Window *window)
+{
+    return add_frame(NULL, window, 0);
+}
+
+static Frame *find_resizable(Frame *frame, ResizeDirection dir)
+{
+    if (dir == RESIZE_DIRECTION_AUTO) {
+        return frame;
+    }
+
+    while (frame->parent) {
+        if (dir == RESIZE_DIRECTION_VERTICAL && frame->parent->vertical) {
+            return frame;
+        }
+        if (dir == RESIZE_DIRECTION_HORIZONTAL && !frame->parent->vertical) {
+            return frame;
+        }
+        frame = frame->parent;
+    }
+    return NULL;
+}
+
+void set_frame_size(Frame *frame, int w, int h)
+{
+    int min_w = get_min_w(frame);
+    int min_h = get_min_h(frame);
+    w = MAX(w, min_w);
+    h = MAX(h, min_h);
+    frame->w = w;
+    frame->h = h;
+
+    if (frame->window) {
+        w -= rightmost_frame(frame) ? 0 : 1; // Separator
+        set_window_size(frame->window, w, h);
+        return;
+    }
+
+    if (frame->equal_size) {
+        divide_equally(frame);
+    } else {
+        fix_size(frame);
+    }
+}
+
+void equalize_frame_sizes(Frame *parent)
+{
+    parent->equal_size = true;
+    divide_equally(parent);
+    update_window_coordinates(parent);
+}
+
+void resize_frame(Frame *frame, ResizeDirection dir, int size)
+{
+    frame = find_resizable(frame, dir);
+    if (!frame) {
+        return;
+    }
+
+    Frame *parent = frame->parent;
+    parent->equal_size = false;
+    resize_to(frame, size);
+    update_window_coordinates(parent);
+}
+
+void add_to_frame_size(Frame *frame, ResizeDirection dir, int amount)
+{
+    resize_frame(frame, dir, get_size(frame) + amount);
+}
+
+static void update_frame_coordinates(const Frame *frame, int x, int y)
+{
+    if (frame->window) {
+        set_window_coordinates(frame->window, x, y);
+        return;
+    }
+
+    for (size_t i = 0, n = frame->frames.count; i < n; i++) {
+        const Frame *c = frame->frames.ptrs[i];
+        update_frame_coordinates(c, x, y);
+        if (frame->vertical) {
+            y += c->h;
+        } else {
+            x += c->w;
+        }
+    }
+}
+
+static Frame *get_root_frame(Frame *frame)
+{
+    BUG_ON(!frame);
+    while (frame->parent) {
+        frame = frame->parent;
+    }
+    return frame;
+}
+
+void update_window_coordinates(Frame *frame)
+{
+    update_frame_coordinates(get_root_frame(frame), 0, 0);
+}
+
+Frame *split_frame(Window *window, bool vertical, bool before)
+{
+    Frame *frame = window->frame;
+    Frame *parent = frame->parent;
+    if (!parent || parent->vertical != vertical) {
+        // Reparent window
+        frame->vertical = vertical;
+        add_frame(frame, window, 0);
+        parent = frame;
+    }
+
+    size_t idx = ptr_array_idx(&parent->frames, window->frame);
+    BUG_ON(idx >= parent->frames.count);
+    idx += before ? 0 : 1;
+    frame = add_frame(parent, new_window(window->editor), idx);
+    parent->equal_size = true;
+
+    // Recalculate
+    set_frame_size(parent, parent->w, parent->h);
+    update_window_coordinates(parent);
+    return frame;
+}
+
+// Doesn't really split root but adds new frame between root and its contents
+Frame *split_root_frame(EditorState *e, bool vertical, bool before)
+{
+    Frame *old_root = e->root_frame;
+    Frame *new_root = new_frame();
+    ptr_array_append(&new_root->frames, old_root);
+    old_root->parent = new_root;
+    new_root->vertical = vertical;
+    e->root_frame = new_root;
+
+    Frame *frame = add_frame(new_root, new_window(e), before ? 0 : 1);
+    set_frame_size(new_root, old_root->w, old_root->h);
+    update_window_coordinates(new_root);
+    return frame;
+}
+
+// NOTE: does not remove frame from frame->parent->frames
+static void free_frame(Frame *frame)
+{
+    frame->parent = NULL;
+    ptr_array_free_cb(&frame->frames, FREE_FUNC(free_frame));
+
+    if (frame->window) {
+        window_free(frame->window);
+        frame->window = NULL;
+    }
+
+    free(frame);
+}
+
+void remove_frame(EditorState *e, Frame *frame)
+{
+    Frame *parent = frame->parent;
+    if (!parent) {
+        free_frame(frame);
+        return;
+    }
+
+    ptr_array_remove(&parent->frames, frame);
+    free_frame(frame);
+
+    if (parent->frames.count == 1) {
+        // Replace parent with the only child frame
+        Frame *gp = parent->parent;
+        Frame *c = parent->frames.ptrs[0];
+        c->parent = gp;
+        c->w = parent->w;
+        c->h = parent->h;
+        if (gp) {
+            size_t idx = ptr_array_idx(&gp->frames, parent);
+            BUG_ON(idx >= gp->frames.count);
+            gp->frames.ptrs[idx] = c;
+        } else {
+            e->root_frame = c;
+        }
+        free(parent->frames.ptrs);
+        free(parent);
+        parent = c;
+    }
+
+    // Recalculate
+    set_frame_size(parent, parent->w, parent->h);
+    update_window_coordinates(parent);
+}
+
+void dump_frame(const Frame *frame, size_t level, String *str)
+{
+    sanity_check_frame(frame);
+    string_append_memset(str, ' ', level * 4);
+    string_sprintf(str, "%dx%d", frame->w, frame->h);
+
+    const Window *win = frame->window;
+    if (win) {
+        string_append_byte(str, '\n');
+        string_append_memset(str, ' ', (level + 1) * 4);
+        string_sprintf(str, "%d,%d %dx%d ", win->x, win->y, win->w, win->h);
+        string_append_cstring(str, buffer_filename(win->view->buffer));
+        string_append_byte(str, '\n');
+        return;
+    }
+
+    string_append_cstring(str, frame->vertical ? " V" : " H");
+    string_append_cstring(str, frame->equal_size ? "\n" : " !\n");
+
+    for (size_t i = 0, n = frame->frames.count; i < n; i++) {
+        const Frame *c = frame->frames.ptrs[i];
+        dump_frame(c, level + 1, str);
+    }
+}
+
+#if DEBUG >= 1
+void debug_frame(const Frame *frame)
+{
+    sanity_check_frame(frame);
+    for (size_t i = 0, n = frame->frames.count; i < n; i++) {
+        const Frame *c = frame->frames.ptrs[i];
+        BUG_ON(c->parent != frame);
+        debug_frame(c);
+    }
+}
+#endif