feat(indev): add multi touch gestures (#7078)

examples/others/gestures/lv_example_gestures.c

@@ -0,0 +1,200 @@
+/*******************************************************************
+ *
+ * @file lv_example_gestures.c
+ *
+ * This is a simple example program that demonstrates how to use
+ * the gesture recognition API, please refer to lv_indev_gesture.h or the documentation
+ * for more details
+ *
+ * The application starts with a single rectangle that is scaled when a pinch gesture
+ * is detected. A single finger moves the rectangle around,
+ *
+ * Copyright (c) 2024 EDGEMTech Ltd
+ *
+ * Author: EDGEMTech Ltd, Erik Tagirov (erik.tagirov@edgemtech.ch)
+ *
+ ******************************************************************/
+
+/*********************
+ *      INCLUDES
+ *********************/
+#include "../../lv_examples.h"
+
+#if LV_USE_GESTURE_RECOGNITION && \
+    LV_USE_FLOAT
+
+/*********************
+ *      DEFINES
+ *********************/
+
+#define RECT_INIT_WIDTH 300.0
+#define RECT_INIT_HEIGHT 300.0
+#define RECT_COLOR 0xC1BCFF
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+/**********************
+ *  STATIC PROTOTYPES
+ **********************/
+
+static void label_scale(lv_event_t * gesture_event);
+static void label_move(lv_event_t * event);
+
+/**********************
+ *  STATIC VARIABLES
+ **********************/
+
+static lv_obj_t * label;
+static lv_style_t label_style;
+static float label_width;
+static float label_height;
+static float label_x;
+static float label_y;
+
+/**********************
+ *      MACROS
+ **********************/
+
+/**********************
+ *   GLOBAL FUNCTIONS
+ **********************/
+
+/**
+ * Entry point it creates the screen, and the label
+ * Set event callbacks on the label
+ */
+void lv_example_gestures(void)
+{
+    lv_obj_t * rectangle;
+    lv_obj_t * root_view;
+
+    label_width = RECT_INIT_WIDTH;
+    label_height = RECT_INIT_HEIGHT;
+    label_y = label_x = 300;
+
+    root_view = lv_screen_active();
+
+    lv_obj_set_style_bg_color(root_view, lv_color_hex(0xFFFFFF), LV_PART_MAIN);
+    label = lv_label_create(root_view);
+    lv_obj_remove_flag(root_view, LV_OBJ_FLAG_SCROLLABLE);
+
+    lv_label_set_text(label, "Zoom or move");
+    lv_obj_add_flag(label, LV_OBJ_FLAG_CLICKABLE);
+
+    lv_style_init(&label_style);
+    lv_style_set_bg_color(&label_style, lv_color_hex(RECT_COLOR));
+    lv_style_set_bg_opa(&label_style, LV_OPA_COVER);
+
+    lv_style_set_width(&label_style, (int)label_width);
+    lv_style_set_height(&label_style, (int)label_height);
+
+    lv_style_set_x(&label_style, (int)label_x);
+    lv_style_set_y(&label_style, (int)label_y);
+
+    lv_obj_add_style(label, &label_style, LV_STATE_DEFAULT);
+
+    lv_obj_add_event_cb(label, label_scale, LV_EVENT_GESTURE, label);
+    lv_obj_add_event_cb(label, label_move, LV_EVENT_PRESSING, label);
+
+}
+
+/**********************
+ *   STATIC FUNCTIONS
+ **********************/
+
+/**
+ * Called when a pinch event occurs - scales the label
+ * @param gesture_event point to a LV_EVENT_PINCH event
+ */
+static void label_scale(lv_event_t * gesture_event)
+{
+
+    static int initial_w = -1;
+    static int initial_h = -1;
+    lv_indev_gesture_state_t state;
+    lv_point_t center_pnt;
+    float scale;
+
+    scale = lv_event_get_pinch_scale(gesture_event);
+    state = lv_event_get_gesture_state(gesture_event);
+
+    lv_indev_get_point(lv_indev_active(), &center_pnt);
+
+    if(state == LV_INDEV_GESTURE_STATE_ENDED) {
+        /* Pinch gesture has ended - reset the width/height for the next pinch gesture*/
+        initial_w = -1;
+        initial_h = -1;
+
+        LV_LOG_TRACE("label end scale: %g %d\n", scale, state);
+        return;
+    }
+
+    if(initial_h == -1 || initial_w == -1) {
+
+        LV_ASSERT(state == LV_INDEV_GESTURE_STATE_RECOGNIZED);
+
+        /* Pinch gesture has been recognized - this is the first event in a series of recognized events */
+        /* The scaling is applied relative to the original width/height of the rectangle */
+        initial_w = label_width;
+        initial_h = label_height;
+
+        LV_LOG_TRACE("label start scale: %g\n", scale);
+    }
+
+    /* The gesture has started or is on-going */
+
+    /* Avoids a situation where the rectangle becomes too small,
+     * do not perform the scaling - leave straight away */
+    if(scale < 0.4) {
+        return;
+    }
+
+    label_width = initial_w * scale;
+    label_height = initial_h * scale;
+    label_x = center_pnt.x - label_width / 2;
+    label_y = center_pnt.y - label_height / 2;
+
+    LV_LOG_TRACE("label scale: %g label x: %g label y: %g w: %g h: %g\n",
+                 scale, label_x, label_y, label_width, label_height);
+
+    /* Update position and size */
+    lv_style_set_width(&label_style, (int)label_width);
+    lv_style_set_height(&label_style, (int)label_height);
+    lv_style_set_x(&label_style, (int)label_x);
+    lv_style_set_y(&label_style, (int)label_y);
+
+    lv_obj_add_style(label, &label_style, LV_STATE_DEFAULT);
+}
+
+/**
+ * Called when a LV_EVENT_PRESSING occurs on the rectangle - moves the label
+ * @param event pointer to the event
+ */
+static void label_move(lv_event_t * event)
+{
+    lv_point_t pnt;
+    lv_indev_gesture_state_t state;
+
+    state = lv_event_get_gesture_state(event);
+    lv_indev_get_point(lv_indev_active(), &pnt);
+
+    /* Do not move and when a pinch gesture is ongoing */
+    if(state == LV_INDEV_GESTURE_STATE_RECOGNIZED) {
+        return;
+    }
+
+    LV_LOG_TRACE("label move %p x: %d y: %d\n", event, pnt.x, pnt.y);
+
+    label_x = pnt.x - label_width / 2;
+    label_y = pnt.y - label_height / 2;
+
+    /* Update position */
+    lv_style_set_x(&label_style, (int)label_x);
+    lv_style_set_y(&label_style, (int)label_y);
+
+    lv_obj_add_style(label, &label_style, LV_STATE_DEFAULT);
+}
+
+#endif /* LV_USE_GESTURE_RECOGNITION && LV_USE_FLOAT */

examples/others/gestures/lv_example_gestures.h

@@ -0,0 +1,44 @@
+/*******************************************************************
+ * @file lv_example_gestures.h
+ *
+ * Copyright (c) 2024 EDGEMTech Ltd.
+ *
+ * Author: EDGEMTech Ltd, Erik Tagirov (erik.tagirov@edgemtech.ch)
+ *
+ ******************************************************************/
+
+#ifndef LV_EXAMPLE_GESTURES_H
+#define LV_EXAMPLE_GESTURES_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*********************
+ *      INCLUDES
+ *********************/
+
+/*********************
+ *      DEFINES
+ *********************/
+
+/**********************
+ *      TYPEDEFS
+ **********************/
+
+/**********************
+ * GLOBAL PROTOTYPES
+ **********************/
+
+/* Example entry point */
+void lv_example_gestures(void);
+
+/**********************
+ *      MACROS
+ **********************/
+
+#ifdef __cplusplus
+} /*extern "C"*/
+#endif
+
+#endif /*LV_EXAMPLE_GESTURES_H*/

examples/others/lv_example_others.h

@@ -22,6 +22,7 @@ extern "C" {
 #include "monkey/lv_example_monkey.h"
 #include "observer/lv_example_observer.h"
 #include "snapshot/lv_example_snapshot.h"
+#include "gestures/lv_example_gestures.h"
 
 /*********************
  *      DEFINES