bugfix: properly constraining apps with minimum size

src/miracle_window_management_policy.cpp

@@ -1,6 +1,7 @@
 #define MIR_LOG_COMPONENT "miracle"
 
 #include "miracle_window_management_policy.h"
+#include "window_helpers.h"
 
 #include <mir_toolkit/events/enums.h>
 #include <miral/toolkit_event.h>
@@ -84,7 +85,7 @@ bool MiracleWindowManagementPolicy::handle_keyboard_event(MirKeyboardEvent const
     auto const scan_code = miral::toolkit::mir_keyboard_event_scan_code(event);
     auto const modifiers = miral::toolkit::mir_keyboard_event_modifiers(event) & MODIFIER_MASK;
 
-    if (action == MirKeyboardAction::mir_keyboard_action_down && (modifiers & mir_input_event_modifier_alt))
+    if (action == MirKeyboardAction::mir_keyboard_action_down && (modifiers & mir_input_event_modifier_meta))
     {
         if (scan_code == KEY_ENTER)
         {
@@ -212,7 +213,10 @@ void MiracleWindowManagementPolicy::handle_window_ready(miral::WindowInfo &windo
     for (auto tree : tree_list)
     {
         if (tree->tree.handle_window_ready(window_info))
+        {
+            tree->tree.constrain(window_info);
             break;
+        }
     }
 }
 
@@ -304,6 +308,7 @@ void MiracleWindowManagementPolicy::handle_modify_window(
     miral::WindowInfo &window_info,
     const miral::WindowSpecification &modifications)
 {
+    auto new_mods = modifications;
     if (modifications.state().is_set())
     {
         if (modifications.state().value() == mir_window_state_fullscreen || modifications.state().value() == mir_window_state_maximized)
@@ -322,7 +327,13 @@ void MiracleWindowManagementPolicy::handle_modify_window(
         }
     }
 
-    window_manager_tools.modify_window(window_info.window(), modifications);
+    window_manager_tools.modify_window(window_info.window(), new_mods);
+
+    for (auto tree :tree_list)
+    {
+        if (tree->tree.constrain(window_info))
+            break;
+    }
 }
 
 void MiracleWindowManagementPolicy::handle_raise_window(miral::WindowInfo &window_info)

src/node.cpp

@@ -519,36 +519,12 @@ bool Node::minimize(std::shared_ptr<Node>& node)
 
 int Node::get_min_width()
 {
-    if (is_window())
-    {
-        miral::WindowInfo& info = tools.info_for(window);
-        return info.min_width().as_int();
-    }
-
-    int min_width = 50;
-    for (auto node : sub_nodes)
-    {
-        min_width = std::max(node->get_min_width(), min_width);
-    }
-
-    return min_width;
+    return 50;
 }
 
 int Node::get_min_height()
 {
-    if (is_window())
-    {
-        miral::WindowInfo& info = tools.info_for(window);
-        return info.min_height().as_int();
-    }
-
-    int min_height = 50;
-    for (auto node : sub_nodes)
-    {
-        min_height = std::max(node->get_min_height(), min_height);
-    }
-
-    return min_height;
+    return 50;
 }
 
 void Node::_set_window_rectangle(geom::Rectangle area)
@@ -562,4 +538,22 @@ void Node::_set_window_rectangle(geom::Rectangle area)
         child.move_to(visible_rect.top_left);
         child.resize(visible_rect.size);
     }
+}
+
+void Node::constrain()
+{
+    if (is_window())
+    {
+        auto& info = tools.info_for(window);
+        if (window_helpers::is_window_fullscreen(info.state()))
+            info.clip_area(mir::optional_value<geom::Rectangle>());
+        else
+            info.clip_area(get_visible_area());
+        return;
+    }
+
+    for (auto node : sub_nodes)
+    {
+        node->constrain();
+    }
 }

src/node.h

@@ -89,6 +89,7 @@ class Node : public std::enable_shared_from_this<Node>
     int get_gap_x() { return gap_x; }
     int get_gap_y() { return gap_y; }
     std::vector<std::shared_ptr<Node>> const& get_sub_nodes() { return sub_nodes; }
+    void constrain();
 
 private:
     std::shared_ptr<Node> parent;

src/window_tree.cpp

@@ -34,19 +34,19 @@ WindowTree::WindowTree(
 
 miral::WindowSpecification WindowTree::allocate_position(const miral::WindowSpecification &requested_specification)
 {
+    miral::WindowSpecification new_spec = requested_specification;
+    new_spec.min_width() = geom::Width{0};
+    new_spec.max_width() = geom::Width{std::numeric_limits<int>::max()};
+    new_spec.min_height() = geom::Height{0};
+    new_spec.max_height() = geom::Height{std::numeric_limits<int>::max()};
     if (requested_specification.state().is_set() && window_helpers::is_window_fullscreen(requested_specification.state().value()))
     {
-        return requested_specification;
+        return new_spec;
     }
 
-    miral::WindowSpecification new_spec = requested_specification;
     auto rect = get_active_lane()->new_node_position();
     new_spec.size() = rect.size;
     new_spec.top_left() = rect.top_left;
-    new_spec.min_width() = geom::Width{0};
-    new_spec.max_width() = geom::Width{std::numeric_limits<int>::max()};
-    new_spec.min_height() = geom::Height{0};
-    new_spec.max_height() = geom::Height{std::numeric_limits<int>::max()};
     return new_spec;
 }
 
@@ -609,5 +609,21 @@ bool WindowTree::confirm_placement_on_display(
         break;
     }
 
+    return true;
+}
+
+bool WindowTree::constrain(miral::WindowInfo &window_info)
+{
+    auto node = root_lane->find_node_for_window(window_info.window());
+    if (!node)
+        return false;
+
+    if (!node->get_parent())
+    {
+        std::cerr << "Unable to constrain node without parent\n";
+        return true;
+    }
+
+    node->get_parent()->constrain();
     return true;
 }

src/window_tree.h

@@ -93,6 +93,9 @@ class WindowTree
         MirWindowState new_state,
         mir::geometry::Rectangle &new_placement);
 
+    /// Constrains the window to its tile if it is in this tree.
+    bool constrain(miral::WindowInfo& window_info);
+
 private:
     miral::WindowManagerTools tools;
     WindowTreeOptions options;