6 files changed, 89 insertions, 12 deletions

diff --git a/applications/goldman/source/input.cpp b/applications/goldman/source/input.cpp
index 0cd6922..c71068c 100644
--- a/applications/goldman/source/input.cpp
+++ b/applications/goldman/source/input.cpp
@@ -5,15 +5,51 @@
 
   euler::syscall::set_thread_name("input thread");
 
+  window *window_being_moved = 0;
+  bool was_mouse_down_before = false;
+
   while (true) {
 
     auto result = euler::syscall::get_input_packet();
     if (std::holds_alternative<euler::syscall::mouse_packet>(result)) {
       auto packet = std::get<euler::syscall::mouse_packet>(result);
+
       r->lock();
+
+      int old_x, old_y;
+      r->get_cursor(old_x, old_y);
       r->bump_cursor(packet.x_changed, packet.y_changed);
+      int new_x, new_y;
+      r->get_cursor(new_x, new_y);
+
+      if (window_being_moved != 0) {
+        if (r->windows.size() == 0 || r->windows.back() != window_being_moved)
+          window_being_moved = 0;
+        else {
+          r->windows.back()->x += new_x - old_x;
+          r->windows.back()->y += new_y - old_y;
+          if (!packet.left_button_down)
+            window_being_moved = 0;
+        }
+      }
+
+      else if (packet.left_button_down && !was_mouse_down_before)
+        for (auto it = r->windows.rbegin(); it != r->windows.rend(); ++it)
+          if (new_x >= (*it)->x && new_y >= (*it)->y &&
+              new_x < (*it)->x + (*it)->contents_with_decorations. width &&
+              new_y < (*it)->y + (*it)->contents_with_decorations.height) {
+            r->move_window_to_front(--it.base());
+            //it is now invalidated, but our window is now r->windows.back()
+            if (new_y < r->windows.back()->y + window::title_height)
+              window_being_moved = r->windows.back();
+            break;
+          }
+
       r->unlock();
       r->dispatch_render();
+
+      was_mouse_down_before = packet.left_button_down;
+
     }
 
   }
diff --git a/applications/goldman/source/renderer.cpp b/applications/goldman/source/renderer.cpp
index 7a5e6b5..4d9beda 100644
--- a/applications/goldman/source/renderer.cpp
+++ b/applications/goldman/source/renderer.cpp
@@ -49,14 +49,15 @@ void renderer::do_render() {
 
   double_buffer.copy_from(background, 0, 0);
 
-  for (auto it = windows.begin(); it != windows.end(); ++it)
-
+  for (auto it = windows.begin(); it != windows.end(); ++it) {
+    int tx = (*it)->x, ty = (*it)->y, fx = 0, fy = 0;
+    int w = (*it)->contents_with_decorations.width;
+    int h = (*it)->contents_with_decorations.height;
+    daguerre::make_safe(tx, fx, w, 0, double_buffer.width);
+    daguerre::make_safe(ty, fy, h, 0, double_buffer.height);
     double_buffer.copy_from(
-      (*it)->contents_with_decorations, (*it)->x, (*it)->y, 0, 0,
-      std::min((*it)->contents_with_decorations.width,
-               double_buffer.width - (*it)->x),
-      std::min((*it)->contents_with_decorations.height,
-               double_buffer.height - (*it)->y));
+      (*it)->contents_with_decorations, tx, ty, fx, fy, w, h);
+  }
 
   double_buffer.convert_from(
     cursor_background, cursor, cursor_x, cursor_y, 0, 0,
@@ -79,6 +80,11 @@ void renderer::do_render() {
   }
 }
 
+void renderer::get_cursor(int &x_out, int &y_out) {
+  x_out = cursor_x;
+  y_out = cursor_y;
+}
+
 void renderer::bump_cursor(int x_offset, int y_offset) {
 
   cursor_x += x_offset;
@@ -95,6 +101,15 @@ void renderer::bump_cursor(int x_offset, int y_offset) {
 
 }
 
+void renderer::move_window_to_front(std::list<window *>::iterator w) {
+  window *wp = *w;
+  windows.erase(w);
+  if (windows.size() != 0)
+    windows.back()->draw_decorations(false);
+  windows.push_back(wp);
+  wp->draw_decorations(true);
+}
+
 void renderer::add_window(window *w) {
   if (windows.size() != 0)
     windows.back()->draw_decorations(false);
diff --git a/applications/goldman/source/renderer.hpp b/applications/goldman/source/renderer.hpp
index 91afe88..c2e82b2 100644
--- a/applications/goldman/source/renderer.hpp
+++ b/applications/goldman/source/renderer.hpp
@@ -17,9 +17,6 @@ class renderer {
   int cursor_x;
   int cursor_y;
 
-  //bottom to top
-  std::list<window *> windows;
-
   std::mutex mut;
 
   euler::syscall::stream_handle
@@ -28,6 +25,12 @@ class renderer {
   void do_render();
 
 public:
+  //all of the shown windows, sorted from furthest back to furthest front.
+  //while the renderer is not locked, the contents of this can change and
+  //iterators can be invalided. this should not be reordered, added to, or
+  //have elements removed from outside the renderer.
+  std::list<window *> windows;
+
   renderer(
     daguerre::image<daguerre::hilbert_color> &&framebuffer,
     daguerre::image<daguerre::hilbert_color> &&background,
@@ -53,8 +56,19 @@ public:
     euler::syscall::write_to_stream(dispatcher_handle_1, 1, &byte);
   }
 
+  //gets the current position of the cursor. this should
+  //only be called while the renderer is locked.
+  void get_cursor(int &x_out, int &y_out);
+
+  //this adds x_offset and y_offset to the current cursor position, and then
+  //clamps the cursor position to have its top-left pixel inside the frame.
+  //this should only be called while the renderer is locked.
   void bump_cursor(int x_offset, int y_offset);
 
+  //moves the pointed to window to the front of the window stack.
+  //this should only be called while the renderer is locked.
+  void move_window_to_front(std::list<window *>::iterator w);
+
   void    add_window(window *w);
   void remove_window(window *w);
 
diff --git a/applications/goldman/source/socket.cpp b/applications/goldman/source/socket.cpp
index aa9b85e..79849df 100644
--- a/applications/goldman/source/socket.cpp
+++ b/applications/goldman/source/socket.cpp
@@ -129,7 +129,10 @@ struct socket_state {
 
   euler::syscall::set_thread_name("socket thread");
 
-  window *w = new window();
+  int x, y;
+  r->get_cursor(x, y);
+
+  window *w = new window(x, y);
   socket_state *state = new socket_state {
     .socket = socket, .w = w };
 
diff --git a/applications/goldman/source/window.cpp b/applications/goldman/source/window.cpp
index fe5212a..3f122ca 100644
--- a/applications/goldman/source/window.cpp
+++ b/applications/goldman/source/window.cpp
@@ -11,12 +11,16 @@ daguerre::hilbert_color border_color_not_top;
 daguerre::hilbert_color title_color;
 
 void window::set_size(int width, int height) {
+  int center_x = x + contents_with_decorations. width / 2;
+  int center_y = y + contents_with_decorations.height / 2;
   contents_with_decorations =
     daguerre::image<daguerre::hilbert_color>(width + 4, height + 18);
   contents = daguerre::image<daguerre::hilbert_color>(
     width, height,
     &contents_with_decorations.at(2, 16),
     contents_with_decorations.buffer_pitch, false);
+  x = center_x - contents_with_decorations. width / 2;
+  y = center_y - contents_with_decorations.height / 2;
 }
 
 void title_converter(
@@ -40,6 +44,7 @@ void window::draw_decorations(bool top) {
 
   static_assert( decorations_extra_width ==  4);
   static_assert(decorations_extra_height == 18);
+  static_assert(            title_height == 16);
 
   auto border_color = top ? border_color_top : border_color_not_top;
 
diff --git a/applications/goldman/source/window.hpp b/applications/goldman/source/window.hpp
index 5c2d7a0..380e25b 100644
--- a/applications/goldman/source/window.hpp
+++ b/applications/goldman/source/window.hpp
@@ -6,6 +6,7 @@ struct window {
 
   static constexpr int decorations_extra_width  =  4;
   static constexpr int decorations_extra_height = 18;
+  static constexpr int title_height = 16;
 
   daguerre::image<daguerre::hilbert_color> contents_with_decorations;
   daguerre::image<daguerre::hilbert_color> contents;
@@ -20,7 +21,10 @@ struct window {
   void set_size(int width, int height);
   void draw_decorations(bool top);
 
-  inline window() : x(0), y(0), is_shown(false) {
+  inline window(int center_x, int center_y)
+  : x(center_x - decorations_extra_width / 2),
+    y(center_y - decorations_extra_height / 2),
+    is_shown(false) {
     set_size(0, 0);
     draw_decorations(false);
   }