move gaps-specific logic out of con.c and render.c into gaps.c

src/gaps.c

@@ -0,0 +1,106 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ * © 2009 Michael Stapelberg and contributors (see also: LICENSE)
+ *
+ * gaps.c: gaps logic: whether to display gaps at all, and how big
+ *         they should be.
+ *
+ */
+#include "all.h"
+
+/**
+ * Calculates the effective gap sizes for a container.
+ */
+gaps_t calculate_effective_gaps(Con *con) {
+    Con *workspace = con_get_workspace(con);
+    if (workspace == NULL)
+        return (gaps_t){0, 0, 0, 0, 0};
+
+    bool one_child = con_num_visible_children(workspace) <= 1 ||
+                     (con_num_children(workspace) == 1 &&
+                      (TAILQ_FIRST(&(workspace->nodes_head))->layout == L_TABBED ||
+                       TAILQ_FIRST(&(workspace->nodes_head))->layout == L_STACKED));
+
+    if (config.smart_gaps == SMART_GAPS_ON && one_child)
+        return (gaps_t){0, 0, 0, 0, 0};
+
+    gaps_t gaps = {
+        .inner = (workspace->gaps.inner + config.gaps.inner) / 2,
+        .top = 0,
+        .right = 0,
+        .bottom = 0,
+        .left = 0};
+
+    if (config.smart_gaps != SMART_GAPS_INVERSE_OUTER || one_child) {
+        gaps.top = workspace->gaps.top + config.gaps.top;
+        gaps.right = workspace->gaps.right + config.gaps.right;
+        gaps.bottom = workspace->gaps.bottom + config.gaps.bottom;
+        gaps.left = workspace->gaps.left + config.gaps.left;
+    }
+
+    /* Outer gaps are added on top of inner gaps. */
+    gaps.top += 2 * gaps.inner;
+    gaps.right += 2 * gaps.inner;
+    gaps.bottom += 2 * gaps.inner;
+    gaps.left += 2 * gaps.inner;
+
+    return gaps;
+}
+
+/*
+ * Decides whether the container should be inset.
+ */
+bool gaps_should_inset_con(Con *con, int children) {
+    /* Inset direct children of the workspace that are leaf containers or
+       stacked/tabbed containers. */
+    if (con->parent != NULL &&
+        con->parent->type == CT_WORKSPACE &&
+        (con_is_leaf(con) ||
+         (con->layout == L_STACKED || con->layout == L_TABBED))) {
+        return true;
+    }
+
+    /* Inset direct children of vertical or horizontal split containers at any
+       depth in the tree (only leaf containers, not split containers within
+       split containers, to avoid double insets). */
+    if (con_is_leaf(con) &&
+        con->parent != NULL &&
+        con->parent->type == CT_CON &&
+        (con->parent->layout == L_SPLITH ||
+         con->parent->layout == L_SPLITV)) {
+        return true;
+    }
+
+    return false;
+}
+
+/*
+ * Returns whether the given container has an adjacent container in the
+ * specified direction. In other words, this returns true if and only if
+ * the container is not touching the edge of the screen in that direction.
+ */
+bool gaps_has_adjacent_container(Con *con, direction_t direction) {
+    Con *workspace = con_get_workspace(con);
+    Con *fullscreen = con_get_fullscreen_con(workspace, CF_GLOBAL);
+    if (fullscreen == NULL)
+        fullscreen = con_get_fullscreen_con(workspace, CF_OUTPUT);
+
+    /* If this container is fullscreen by itself, there's no adjacent container. */
+    if (con == fullscreen)
+        return false;
+
+    Con *first = con;
+    Con *second = NULL;
+    bool found_neighbor = resize_find_tiling_participants(&first, &second, direction, false);
+    if (!found_neighbor)
+        return false;
+
+    /* If we have an adjacent container and nothing is fullscreen, we consider it. */
+    if (fullscreen == NULL)
+        return true;
+
+    /* For fullscreen containers, only consider the adjacent container if it is also fullscreen. */
+    return con_has_parent(con, fullscreen) && con_has_parent(second, fullscreen);
+}