js: Distinguish manual resizes from device pixel ratio changes

This adds a new callback, rescale_puzzle(), that's called when the
device pixel ratio changes.  This means that resize_puzzle() can safely
set the nominal canvas size, which means that manual resizing of the
puzzle now sticks.

Still missing: paying attention to the device pixel ratio when choosing
the initial (or reset) size.

1 files changed, 9 insertions, 2 deletions

diff --git a/emcc.c b/emcc.c
index 4591ccb..605938b 100644
--- a/emcc.c
+++ b/emcc.c
@@ -195,8 +195,8 @@ static void resize(void)
     canvas_h = h;
 }
 
-/* Called from JS when the user uses the resize handle */
-void resize_puzzle(int w, int h)
+/* Called from JS when the device pixel ratio changes */
+void rescale_puzzle(int w, int h)
 {
     midend_size(me, &w, &h, true);
     if (canvas_w != w || canvas_h != h) { 
@@ -207,6 +207,13 @@ void resize_puzzle(int w, int h)
     }
 }
 
+/* Called from JS when the user uses the resize handle */
+void resize_puzzle(int w, int h)
+{
+    rescale_puzzle(w, h);
+    js_canvas_set_nominal_size();
+}
+
 /* Called from JS when the user uses the restore button */
 void restore_puzzle_size(int w, int h)
 {