GUI module example: 2 button dialog (#308)

* GUI: reusable module example

applications/gui/modules/dialog.c

@@ -0,0 +1,106 @@
+#include "dialog.h"
+#include <furi.h>
+
+struct Dialog {
+    View* view;
+    void* context;
+    DialogResultCallback callback;
+};
+
+typedef struct {
+    const char* header_text;
+    const char* text;
+    const char* left_text;
+    const char* right_text;
+} DialogModel;
+
+static void dialog_view_draw_callback(Canvas* canvas, void* _model) {
+    DialogModel* model = _model;
+    // Prepare canvas
+    canvas_clear(canvas);
+    canvas_set_color(canvas, ColorBlack);
+    // Draw header
+    canvas_set_font(canvas, FontPrimary);
+    canvas_draw_str(canvas, 2, 10, model->header_text);
+    // Draw text
+    canvas_set_font(canvas, FontSecondary);
+    canvas_draw_str(canvas, 5, 22, model->text);
+    // Draw buttons
+    uint8_t bottom_base_line = canvas_height(canvas) - 2;
+    canvas_set_font(canvas, FontPrimary);
+    canvas_draw_str(canvas, 5, bottom_base_line, model->left_text);
+    canvas_draw_str(canvas, 69, bottom_base_line, model->right_text);
+}
+
+static bool dialog_view_input_callback(InputEvent* event, void* context) {
+    Dialog* dialog = context;
+    // Process key presses only
+    if(event->state && dialog->callback) {
+        if(event->input == InputLeft) {
+            dialog->callback(DialogResultLeft, dialog->context);
+        } else if(event->input == InputRight) {
+            dialog->callback(DialogResultRight, dialog->context);
+        }
+    }
+    // All input events consumed
+    return true;
+}
+
+Dialog* dialog_alloc() {
+    Dialog* dialog = furi_alloc(sizeof(Dialog));
+    dialog->view = view_alloc();
+    view_set_context(dialog->view, dialog);
+    view_allocate_model(dialog->view, ViewModelTypeLockFree, sizeof(DialogModel));
+    view_set_draw_callback(dialog->view, dialog_view_draw_callback);
+    view_set_input_callback(dialog->view, dialog_view_input_callback);
+    return dialog;
+}
+
+void dialog_free(Dialog* dialog) {
+    furi_assert(dialog);
+    view_free(dialog->view);
+    free(dialog);
+}
+
+View* dialog_get_view(Dialog* dialog) {
+    furi_assert(dialog);
+    return dialog->view;
+}
+
+void dialog_set_result_callback(Dialog* dialog, DialogResultCallback callback) {
+    furi_assert(dialog);
+    dialog->callback = callback;
+}
+
+void dialog_set_context(Dialog* dialog, void* context) {
+    furi_assert(dialog);
+    dialog->context = context;
+}
+
+void dialog_set_header_text(Dialog* dialog, const char* text) {
+    furi_assert(dialog);
+    furi_assert(text);
+    with_view_model(
+        dialog->view, (DialogModel * model) { model->header_text = text; });
+}
+
+void dialog_set_text(Dialog* dialog, const char* text) {
+    furi_assert(dialog);
+    furi_assert(text);
+    with_view_model(
+        dialog->view, (DialogModel * model) { model->text = text; });
+}
+
+void dialog_set_left_button_text(Dialog* dialog, const char* text) {
+    furi_assert(dialog);
+    furi_assert(text);
+    with_view_model(
+        dialog->view, (DialogModel * model) { model->left_text = text; });
+}
+
+void dialog_set_right_button_text(Dialog* dialog, const char* text) {
+    furi_assert(dialog);
+    furi_assert(text);
+    with_view_model(
+        dialog->view, (DialogModel * model) { model->right_text = text; });
+}

applications/gui/modules/dialog.h

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+#pragma once
+
+#include <gui/view.h>
+
+/* Dialog anonymous structure */
+typedef struct Dialog Dialog;
+
+/* Dialog result */
+typedef enum {
+    DialogResultLeft,
+    DialogResultRight,
+} DialogResult;
+
+/* Dialog result callback type
+ * @warning comes from GUI thread
+ */
+typedef void (*DialogResultCallback)(DialogResult result, void* context);
+
+/* Allocate and initialize dialog
+ * This dialog used to ask simple questions like Yes/
+ */
+Dialog* dialog_alloc();
+
+/* Deinitialize and free dialog
+ * @param dialog - Dialog instance
+ */
+void dialog_free(Dialog* dialog);
+
+/* Get dialog view
+ * @param dialog - Dialog instance
+ * @return View instance that can be used for embedding
+ */
+View* dialog_get_view(Dialog* dialog);
+
+/* Set dialog header text
+ * @param dialog - Dialog instance
+ * @param text - text to be shown
+ */
+void dialog_set_result_callback(Dialog* dialog, DialogResultCallback callback);
+
+/* Set dialog header text
+ * @param dialog - Dialog instance
+ * @param context - context pointer, will be passed to result callback
+ */
+void dialog_set_context(Dialog* dialog, void* context);
+
+/* Set dialog header text
+ * @param dialog - Dialog instance
+ * @param text - text to be shown
+ */
+void dialog_set_header_text(Dialog* dialog, const char* text);
+
+/* Set dialog text
+ * @param dialog - Dialog instance
+ * @param text - text to be shown
+ */
+void dialog_set_text(Dialog* dialog, const char* text);
+
+/* Set left button text
+ * @param dialog - Dialog instance
+ * @param text - text to be shown
+ */
+void dialog_set_left_button_text(Dialog* dialog, const char* text);
+
+/* Set right button text
+ * @param dialog - Dialog instance
+ * @param text - text to be shown
+ */
+void dialog_set_right_button_text(Dialog* dialog, const char* text);