feat: client 的任务栏标题点击行为根据 client 窗口的遮挡状态进行

- 当点击 client 在任务中的标题时，如果 client 被其他窗口遮挡，则将其显
示出来，否则切换其 minimize 属性
- 新增 rect 模块用于辅助判断 client 的遮挡状态，添加
rect_intersection/rect_subtract/rect_subtract_many 函数
- client 模块新增 client_get_obscured_state 计算 client 窗口被遮挡状态
- action 模块新增 change_client_state_dwim，实现上述的 client 状态切换

CMakeLists.txt

@@ -43,6 +43,7 @@ add_executable(${APP_NAME}
     ${SOURCE_DIR}/xres.c
     ${SOURCE_DIR}/status.c
     ${SOURCE_DIR}/audio.c
+    ${SOURCE_DIR}/rect.c
 )
 
 find_package(PkgConfig REQUIRED)

src/action.c

@@ -118,3 +118,23 @@ void kill_client(const user_action_arg_t *arg) {
     client_kill(wm.client_focused);
   }
 }
+
+/**
+ * @brief 根据 client 的当前状态切换 client 下一状态
+ * @description 如果当前 client 被遮挡了或者最小化了，则显示出来，否则最小化
+ */
+void change_client_state_dwim(const user_action_arg_t *arg) {
+  client_t *client = (client_t *)arg->ptr;
+  if (!client) return;
+
+  if (client != wm.client_stack_list &&
+      client_get_obscured_state(client, wm.client_stack_list) !=
+        obscured_none) {
+    client_stack_raise(client);
+    client_focus(client);
+    return;
+  }
+
+  client_set_minimize(client, !client->minimize);
+  if (!client->minimize) client_stack_raise(client);
+}

src/action.h

@@ -63,3 +63,4 @@ void toggle_client_fullscreen(const user_action_arg_t *arg);
 void toggle_client_maximize(const user_action_arg_t *arg);
 void toggle_client_minimize(const user_action_arg_t *arg);
 void kill_client(const user_action_arg_t *arg);
+void change_client_state_dwim(const user_action_arg_t *arg);

src/client.c

@@ -10,6 +10,7 @@
 #include "atoms-extern.h"
 #include "base.h"
 #include "monitor.h"
+#include "rect.h"
 #include "types.h"
 #include "utils.h"
 #include "wm.h"
@@ -646,3 +647,50 @@ void client_stack_raise(client_t *client) {
 bool client_is_visible(client_t *client) {
   return client->tags & client->monitor->selected_tag->mask;
 }
+
+static inline rect_t client_to_rect(client_t *client) {
+  return (rect_t){
+    .x1 = client->geometry.x,
+    .y1 = client->geometry.y,
+    .x2 = client->geometry.x + (int32_t)client_width(client),
+    .y2 = client->geometry.y + (int32_t)client_height(client),
+  };
+}
+
+obscured_t client_get_obscured_state(client_t *client, client_t *client_stack) {
+  if (!client || !client_stack) return obscured_none;
+
+  rect_t source = client_to_rect(client);
+  size_t clip_count = 0;
+  size_t clip_capacity = 0;
+  rect_t *clips = nullptr;
+
+  bool has_overlap = false;
+  for (client_t *c = client_stack; c; c = c->stack_next) {
+    if (c == client) break;
+    if (c->minimize || !client_is_visible(c)) continue;
+
+    rect_t clip = client_to_rect(c);
+    if (!rect_intersection(source, clip, nullptr)) continue;
+
+    has_overlap = true;
+    if (clip_count == clip_capacity) {
+      clip_capacity = clip_capacity ? clip_capacity * 2 : 4;
+      p_realloc(&clips, clip_capacity);
+    }
+    clips[clip_count++] = clip;
+  }
+
+  if (!has_overlap) {
+    p_delete(&clips);
+    return obscured_none;
+  }
+
+  rect_t *remaining = nullptr;
+  size_t remaining_count =
+    rect_subtract_many(source, clips, clip_count, &remaining);
+
+  p_delete(&clips);
+  p_delete(&remaining);
+  return remaining_count == 0 ? obscured_fully : obscured_partially;
+}

src/client.h

@@ -61,6 +61,13 @@ void client_stack_raise(client_t *client);
 
 bool client_is_visible(client_t *client);
 
+typedef enum obscured_t {
+  obscured_none,
+  obscured_partially,
+  obscured_fully,
+} obscured_t;
+obscured_t client_get_obscured_state(client_t *client, client_t *client_stack);
+
 static inline uint16_t client_width(client_t *c) {
   return c->geometry.width + c->border_width * 2;
 }

src/default_config.h

@@ -29,7 +29,13 @@ static const char *const active_border_color = "#005577";
 
 static const button_t button_list[] = {
   {click_tag, modifier_none, button_left, select_tag_of_current_monitor, {0}},
-  {click_client_name, modifier_none, button_left, toggle_client_minimize, {0}},
+  {
+    click_client_name,
+    modifier_none,
+    button_left,
+    change_client_state_dwim,
+    {0},
+  },
 };
 
 #define TAGKEYS(KEY, TAG)                                                  \

src/rect.c

@@ -0,0 +1,155 @@
+#include "rect.h"
+
+#include "utils.h"
+
+static inline bool rect_valid(rect_t rect) {
+  return rect.x1 < rect.x2 && rect.y1 < rect.y2;
+}
+
+/* 将一个合法矩形追加到动态矩形数组中。 */
+static inline void rect_list_append(rect_t **list, size_t *length,
+                                    size_t *capacity, rect_t rect) {
+  if (!rect_valid(rect)) return;
+
+  if (*length == *capacity) {
+    *capacity = *capacity ? *capacity * 2 : 4;
+    p_realloc(list, *capacity);
+  }
+  (*list)[(*length)++] = rect;
+}
+
+bool rect_intersection(rect_t a, rect_t b, rect_t *intersection) {
+  if (!rect_valid(a) || !rect_valid(b)) return false;
+
+  rect_t overlap = {
+    .x1 = MAX(a.x1, b.x1),
+    .y1 = MAX(a.y1, b.y1),
+    .x2 = MIN(a.x2, b.x2),
+    .y2 = MIN(a.y2, b.y2),
+  };
+  if (!rect_valid(overlap)) return false;
+
+  if (intersection) *intersection = overlap;
+  return true;
+}
+
+size_t rect_subtract(rect_t source, rect_t clip, rect_t remaining[4]) {
+  if (!rect_valid(source)) return 0;
+
+  rect_t overlap;
+  if (!rect_intersection(source, clip, &overlap)) {
+    if (remaining) remaining[0] = source;
+    return 1;
+  }
+
+  size_t count = 0;
+  /*
+   * source:  [sx1,sx2) x [sy1,sy2)
+   * overlap: [ox1,ox2) x [oy1,oy2) = source 与 clip 的交集
+   *
+   * y=sy1   ┌───────────────────────────────────────────┐
+   *         │                     TOP                   │
+   *         │      UL                             UR    │
+   * y=oy1   ├───────────────┬───────────────┬───────────┤
+   *         │     LEFT      │    OVERLAP    │   RIGHT   │
+   * y=oy2   ├───────────────┴───────────────┴───────────┤
+   *         │      LL                             LR    │
+   *         │                    BOTTOM                 │
+   * y=sy2   └───────────────────────────────────────────┘
+   *        x=sx1           x=ox1           x=ox2       x=sx2
+   *
+   * 角块归属：
+   * UL、UR 属于 TOP
+   * LL、LR 属于 BOTTOM
+   * LEFT/RIGHT 只覆盖 y ∈ [oy1, oy2)，因此不会包含四个角块。
+   */
+  rect_t parts[] = {
+    /* top */
+    {
+      .x1 = source.x1,
+      .y1 = source.y1,
+      .x2 = source.x2,
+      .y2 = overlap.y1,
+    },
+    /* bottom */
+    {
+      .x1 = source.x1,
+      .y1 = overlap.y2,
+      .x2 = source.x2,
+      .y2 = source.y2,
+    },
+    /* left */
+    {
+      .x1 = source.x1,
+      .y1 = overlap.y1,
+      .x2 = overlap.x1,
+      .y2 = overlap.y2,
+    },
+    /* right */
+    {
+      .x1 = overlap.x2,
+      .y1 = overlap.y1,
+      .x2 = source.x2,
+      .y2 = overlap.y2,
+    },
+  };
+
+  for (size_t i = 0; i < countof(parts); i++) {
+    if (!rect_valid(parts[i])) continue;
+    if (remaining) remaining[count] = parts[i];
+    count++;
+  }
+
+  return count;
+}
+
+size_t rect_subtract_many(rect_t source, const rect_t clips[],
+                          size_t clip_count, rect_t **remaining) {
+  /*
+   * 实现说明：
+   * 初始剩余集合为 {source}，然后依次处理每个 clip：
+   * 1) 用 clip 去减当前集合中的每个碎片
+   * 2) 将产生的新碎片合并到 next 集合
+   * 3) 用 next 替换 current，进入下一轮
+   * 最终 current 即 source - clips[0] - clips[1] - ... 的结果。
+   */
+  if (remaining) *remaining = nullptr;
+  if (!rect_valid(source)) return 0;
+
+  size_t current_length = 1;
+  size_t current_capacity = 1;
+  rect_t *current = p_new(rect_t, current_capacity);
+  current[0] = source;
+
+  if (clips) {
+    for (size_t i = 0; i < clip_count && current_length > 0; i++) {
+      rect_t clip = clips[i];
+      if (!rect_valid(clip)) continue;
+
+      size_t next_length = 0;
+      size_t next_capacity = current_length ? current_length : 1;
+      rect_t *next = p_new(rect_t, next_capacity);
+
+      for (size_t j = 0; j < current_length; j++) {
+        rect_t fragments[4];
+        size_t fragment_count = rect_subtract(current[j], clip, fragments);
+        for (size_t k = 0; k < fragment_count; k++) {
+          rect_list_append(&next, &next_length, &next_capacity, fragments[k]);
+        }
+      }
+
+      p_delete(&current);
+      current = next;
+      current_length = next_length;
+      current_capacity = next_capacity;
+    }
+  }
+
+  if (remaining) {
+    *remaining = current;
+  } else {
+    p_delete(&current);
+  }
+
+  return current_length;
+}

src/rect.h

@@ -0,0 +1,41 @@
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct rect_t {
+  int32_t x1;
+  int32_t y1;
+  int32_t x2;
+  int32_t y2;
+} rect_t;
+
+bool rect_intersection(rect_t a, rect_t b, rect_t *intersection);
+size_t rect_subtract(rect_t source, rect_t clip, rect_t remaining[4]);
+/**
+ * @brief 从 source 中按顺序减去 clips 中的多个矩形
+ * @param source 源矩形
+ * @param clips 要减去的矩形数组，可为 nullptr
+ * @param clip_count clips 的长度
+ * @param remaining 输出剩余矩形数组；若不为 nullptr，则由函数分配内存并由调用方释放
+ * @return 剩余矩形数量
+ *
+ * @code{.c}
+ * rect_t source = {.x1 = 0, .y1 = 0, .x2 = 100, .y2 = 80};
+ * rect_t clips[] = {
+ *   {.x1 = 10, .y1 = 10, .x2 = 40, .y2 = 40},
+ *   {.x1 = 30, .y1 = 20, .x2 = 70, .y2 = 60},
+ * };
+ *
+ * rect_t *remaining = nullptr;
+ * size_t count = rect_subtract_many(source, clips, 2, &remaining);
+ *
+ * for (size_t i = 0; i < count; i++) {
+ *   // use remaining[i]
+ * }
+ *
+ * free(remaining);
+ * @endcode
+ */
+size_t rect_subtract_many(rect_t source, const rect_t clips[],
+                          size_t clip_count, rect_t **remaining);