From 269455d8ad243678f2a09d7c2030aefca9549232 Mon Sep 17 00:00:00 2001
From: c vw <dl1ycf@darc.de>
Date: Fri, 22 Apr 2022 18:31:05 +0200
Subject: [PATCH] Touchscreen-Friendly ComboBoxes: use them in any case for the
 discovery screen, when starting the radio set default to "mouse friendly"

---
 discovery.c |  7 ++++++-
 radio.c     | 42 ++++++++++++++++++++++++++++++++++++++----
 2 files changed, 44 insertions(+), 5 deletions(-)

diff --git a/discovery.c b/discovery.c
index 956439a..06926da 100644
--- a/discovery.c
+++ b/discovery.c
@@ -196,6 +196,11 @@ g_print("connect_cb: %s:%d\n",host_addr,host_port);
 void discovery() {
 //fprintf(stderr,"discovery\n");
 
+  //
+  // On the discovery screen, make the combo-boxes "touchscreen-friendly"
+  //
+  optimize_for_touchscreen=1;
+
   protocols_restore_state();
 
   selected_device=0;
@@ -443,8 +448,8 @@ fprintf(stderr,"%p Protocol=%d name=%s\n",d,d->protocol,d->name);
               gtk_combo_box_set_active_id(GTK_COMBO_BOX(apps_combobox[row]),
                   "stemlab_sdr_transceiver_hpsdr");
             }
-            gtk_widget_show(apps_combobox[row]);
             my_combo_attach(GTK_GRID(grid), apps_combobox[row], 4, row, 1, 1);
+            gtk_widget_show(apps_combobox[row]);
           }
         }
 #endif
diff --git a/radio.c b/radio.c
index b879522..d50e5d5 100644
--- a/radio.c
+++ b/radio.c
@@ -350,7 +350,7 @@ double meter_calibration=0.0;
 double display_calibration=0.0;
 
 int can_transmit=0;
-int optimize_for_touchscreen=1;
+int optimize_for_touchscreen=0;
 
 gboolean duplex=FALSE;
 gboolean mute_rx_while_transmitting=FALSE;
@@ -685,6 +685,14 @@ void start_radio() {
 //g_print("start_radio: selected radio=%p device=%d\n",radio,radio->device);
   gdk_window_set_cursor(gtk_widget_get_window(top_window),gdk_cursor_new(GDK_WATCH));
 
+  //
+  // In the discovery dialog, we have set the combobox behaviour to
+  // "touchscreen friendly". Now we set it to "mouse friendly"
+  // but this can be overridden in the RADIO menu or when reading
+  // from the props file
+  //
+  optimize_for_touchscreen=0;
+
   protocol=radio->protocol;
   device=radio->device;
 
@@ -2872,17 +2880,43 @@ int remote_start(void *data) {
 }
 #endif
 
+///////////////////////////////////////////////////////////////////////////////////////////
+//
+// A mechanism to make ComboBoxes "touchscreen-friendly".
+// If the variable "optimize_for_touchscreen" is nonzero, their
+// behaviour is modified such that they only react on "button release"
+// events, the first release event pops up the menu, the second one makes
+// the choice.
+//
+// This is necessary since a "slow click" (with some delay between press and release)
+// leads you nowhere: the PRESS event lets the menu open, it grabs the focus, and
+// the RELEASE event makes the choice. With a mouse this is no problem since you
+// hold the button while making a choice, but with a touch-screen it may make the
+// GUI un-usable.
+//
+// The variable "optimize_for_touchscreen" can be changed in the RADIO menu (or whereever
+// it is decided to move this).
+//
+///////////////////////////////////////////////////////////////////////////////////////////
+
 static gboolean eventbox_callback(GtkWidget *widget, GdkEvent *event, gpointer data)
 {
+  //
+  // data is the ComboBox that is contained in the EventBox
+  //
   if (event->type == GDK_BUTTON_RELEASE) {
     gtk_combo_box_popup(GTK_COMBO_BOX(data));
-    return TRUE;
   }
-  return FALSE;
+  return TRUE;
 }
 
 //
-// This function replaces gtk_grid_attach for a newly created combo-box
+// This function has to be called instead of "gtk_grid_attach" for ComboBoxes.
+// Basically, it creates an EventBox and puts the ComboBox therein,
+// such that all events (mouse clicks) go to the EventBox. This ignores
+// everything except "button release" events, in this case it lets the ComboBox
+// pop-up the menu which then goes to the foreground.
+// Then, the choice can be made from the menu in the usual way.
 //
 void my_combo_attach(GtkGrid *grid, GtkWidget *combo, int row, int col, int spanrow, int spancol)
 {
-- 
2.45.2