Add Binder helper methods (#1465)

* Add binder, fix focus on remote btn delete
* Use binder for freqman edit

firmware/application/binder.hpp

@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2023 Kyle Reed
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __BINDER_H__
+#define __BINDER_H__
+
+#include "ui.hpp"
+#include "ui_navigation.hpp"
+#include "ui_widget.hpp"
+
+namespace ui {
+
+/* Default no-op binding callback. */
+struct NoOp {
+    NoOp() {}
+    template <typename T>
+    void operator()(T) const {}
+};
+
+/* The gist of the bind functions is to bind a control
+ * to a value.
+ *     bind(control, value)
+ *
+ * An optional callback can be specified which will be called
+ * when the control's value is changed.
+ *    bind(control, value, [](auto new_val) { ... });
+ *
+ * Some controls need a reference to the NavigationView so
+ * edit dialogs (like text_prompt) can be launched.
+ *    bind(control, value, nav, [](auto new_val) { ... });
+ *
+ * Be careful with lifetime of captured objects. Most things
+ * are captured by reference so the caller will need to ensure
+ * adequate lifetime of the referenced instances.
+ */
+
+template <typename T, typename Fn = NoOp>
+void bind(NumberField& field, T& value, Fn fn = Fn{}) {
+    field.set_value(value);
+    field.on_change = [&value, fn](int32_t v) {
+        value = v;
+        fn(value);
+    };
+}
+
+template <typename T, typename Fn = NoOp>
+void bind(OptionsField& field, T& value, Fn fn = Fn{}) {
+    field.set_by_value(static_cast<int32_t>(value));
+    field.on_change = [&value, fn](size_t, auto v) {
+        value = static_cast<T>(v);
+        fn(value);
+    };
+}
+
+template <typename T, typename Fn = NoOp>
+void bind(FrequencyField& field, T& value, NavigationView& nav, Fn fn = Fn{}) {
+    field.set_value(value);
+    field.on_change = [&value, fn](rf::Frequency f) {
+        value = f;
+        fn(value);
+    };
+    field.on_edit = [&field, &value, &nav]() {
+        auto freq_view = nav.push<FrequencyKeypadView>(value);
+        freq_view->on_changed = [&field](rf::Frequency f) {
+            field.set_value(f);
+        };
+    };
+}
+
+template <typename T, typename Fn = NoOp>
+void bind(TextField& field, T& value, NavigationView& nav, Fn fn = Fn{}) {
+    field.set_text(value);
+    field.on_change = [&value, fn](TextField& tf) {
+        value = tf.get_text();
+        fn(value);
+    };
+    // text_prompt needs a mutable working buffer.
+    // Capture a new string and make the lambda mutable so it can be modified.
+    field.on_select = [&nav, buf = std::string{}](TextField& tf) mutable {
+        buf = tf.get_text();
+        text_prompt(nav, buf, /*max_length*/ 255,
+                    [&tf](std::string& str) {
+                        tf.set_text(str);
+                    });
+    };
+}
+
+}  // namespace ui
+
+#endif /*__BINDER_H__*/