ViewDispatcher example

ui/viewdispatcher_demo/demo.c

@@ -0,0 +1,145 @@
+/*
+
+This is an example of using a ViewDispatcher.  It is a simple Hello World program that
+allows you to move a cursor around the screen with the arrow keys.  Pressing the OK button
+will switch between two Views (the views share the same callback functions), just have 
+different screen orientations.  Pressing the the back button will exit the program.
+
+The code is from the Message Queue wiki page 
+(https://github.com/jamisonderek/flipper-zero-tutorials/wiki/Message-Queue) and
+also the ViewDispatcher section of the User Interface wiki page
+(https://github.com/jamisonderek/flipper-zero-tutorials/wiki/User-Interface#viewdispatcher).
+
+*/
+
+#include <furi.h>
+#include <gui/gui.h>
+#include <gui/view_dispatcher.h>
+#include <gui/view.h>
+
+typedef enum {
+    MyEventTypeKey,
+    MyEventTypeDone,
+} MyEventType;
+
+typedef struct {
+    MyEventType type; // The reason for this event.
+    InputEvent input; // This data is specific to keypress data.
+} MyEvent;
+
+typedef enum {
+    MyViewId,
+    MyOtherViewId,
+} ViewId;
+
+FuriMessageQueue* queue;
+int x = 32;
+int y = 48;
+ViewId current_view;
+
+static void my_draw_callback(Canvas* canvas, void* context) {
+    UNUSED(context);
+    canvas_set_font(canvas, FontPrimary);
+    canvas_draw_str(canvas, 5, 30, "Hello world");
+    canvas_draw_str_aligned(canvas, x, y, AlignLeft, AlignTop, "^");
+}
+
+static bool my_input_callback(InputEvent* input_event, void* context) {
+    furi_assert(context);
+    bool handled = false;
+    // we set our callback context to be the view_dispatcher.
+    ViewDispatcher* view_dispatcher = context;
+
+    if(input_event->type == InputTypeShort) {
+        if(input_event->key == InputKeyBack) {
+            // Default back handler.
+            handled = false;
+        } else if(input_event->key == InputKeyLeft) {
+            x--;
+            handled = true;
+        } else if(input_event->key == InputKeyRight) {
+            x++;
+            handled = true;
+        } else if(input_event->key == InputKeyUp) {
+            y--;
+            handled = true;
+        } else if(input_event->key == InputKeyDown) {
+            y++;
+            handled = true;
+        } else if(input_event->key == InputKeyOk) {
+            // switch the view!
+            view_dispatcher_send_custom_event(view_dispatcher, 42);
+            handled = true;
+        }
+    }
+
+    return handled;
+}
+
+bool view_dispatcher_navigation_event_callback(void* context) {
+    UNUSED(context);
+    // We did not handle the event, so return false.
+    return false;
+}
+
+bool my_view_dispatcher_custom_event_callback(void* context, uint32_t event) {
+    furi_assert(context);
+    bool handled = false;
+    // we set our callback context to be the view_dispatcher.
+    ViewDispatcher* view_dispatcher = context;
+
+    if(event == 42) {
+        if(current_view == MyViewId) {
+            current_view = MyOtherViewId;
+        } else {
+            current_view = MyViewId;
+        }
+
+        view_dispatcher_switch_to_view(view_dispatcher, current_view);
+        handled = true;
+    }
+
+    // NOTE: The return value is not currently used by the ViewDispatcher.
+    return handled;
+}
+
+int32_t viewdispatcher_demo_app() {
+    ViewDispatcher* view_dispatcher = view_dispatcher_alloc();
+
+    // For this demo, we just use view_dispatcher as our application context.
+    void* my_context = view_dispatcher;
+
+    View* view1 = view_alloc();
+    view_set_context(view1, my_context);
+    view_set_draw_callback(view1, my_draw_callback);
+    view_set_input_callback(view1, my_input_callback);
+    view_set_orientation(view1, ViewOrientationHorizontal);
+
+    View* view2 = view_alloc();
+    view_set_context(view2, my_context);
+    view_set_draw_callback(view2, my_draw_callback);
+    view_set_input_callback(view2, my_input_callback);
+    view_set_orientation(view2, ViewOrientationVertical);
+
+    // set param 1 of custom event callback (impacts tick and navigation too).
+    view_dispatcher_set_event_callback_context(view_dispatcher, my_context);
+    view_dispatcher_set_navigation_event_callback(
+        view_dispatcher, view_dispatcher_navigation_event_callback);
+    view_dispatcher_set_custom_event_callback(
+        view_dispatcher, my_view_dispatcher_custom_event_callback);
+    view_dispatcher_enable_queue(view_dispatcher);
+    view_dispatcher_add_view(view_dispatcher, MyViewId, view1);
+    view_dispatcher_add_view(view_dispatcher, MyOtherViewId, view2);
+
+    Gui* gui = furi_record_open(RECORD_GUI);
+    view_dispatcher_attach_to_gui(view_dispatcher, gui, ViewDispatcherTypeFullscreen);
+    current_view = MyViewId;
+    view_dispatcher_switch_to_view(view_dispatcher, current_view);
+    view_dispatcher_run(view_dispatcher);
+
+    view_dispatcher_remove_view(view_dispatcher, MyViewId);
+    view_dispatcher_remove_view(view_dispatcher, MyOtherViewId);
+    furi_record_close(RECORD_GUI);
+    view_dispatcher_free(view_dispatcher);
+    return 0;
+}