feat(disp): add screen out animations (#3081)

* add screen out animations

* make FADE_ON an alias of FADE_IN for backward compatiblitiy

* revert any changes to lv_indev.c

* format code

* update docs

* disable input if screen animation is active

docs/overview/object.md

@@ -164,8 +164,9 @@ Read the [Layer overview](/overview/layer) section to learn more about layers.
 A new screen can be loaded with animation by using `lv_scr_load_anim(scr, transition_type, time, delay, auto_del)`. The following transition types exist:
 - `LV_SCR_LOAD_ANIM_NONE` Switch immediately after `delay` milliseconds
 - `LV_SCR_LOAD_ANIM_OVER_LEFT/RIGHT/TOP/BOTTOM` Move the new screen over the current towards the given direction
+- `LV_SCR_LOAD_ANIM_OUT_LEFT/RIGHT/TOP/BOTTOM` Move out the old screen over the current towards the given direction
 - `LV_SCR_LOAD_ANIM_MOVE_LEFT/RIGHT/TOP/BOTTOM` Move both the current and new screens towards the given direction
-- `LV_SCR_LOAD_ANIM_FADE_ON` Fade the new screen over the old screen
+- `LV_SCR_LOAD_ANIM_FADE_IN/OUT` Fade the new screen over the old screen, or vice versa
 
 Setting `auto_del` to `true` will automatically delete the old screen when the animation is finished.
 

src/core/lv_disp.c

@@ -27,6 +27,7 @@ static void opa_scale_anim(void * obj, int32_t v);
 static void set_x_anim(void * obj, int32_t v);
 static void set_y_anim(void * obj, int32_t v);
 static void scr_anim_ready(lv_anim_t * a);
+static bool is_out_anim(lv_scr_load_anim_t a);
 
 /**********************
  *  STATIC VARIABLES
@@ -252,6 +253,7 @@ void lv_scr_load_anim(lv_obj_t * new_scr, lv_scr_load_anim_t anim_type, uint32_t
         d->prev_scr = NULL;
     }
 
+    d->draw_prev_over_act = is_out_anim(anim_type);
     d->del_prev = auto_del;
 
     /*Be sure there is no other animation on the screens*/
@@ -328,11 +330,30 @@ void lv_scr_load_anim(lv_obj_t * new_scr, lv_scr_load_anim_t anim_type, uint32_t
             lv_anim_set_exec_cb(&a_old, set_y_anim);
             lv_anim_set_values(&a_old, 0, lv_disp_get_ver_res(d));
             break;
-
-        case LV_SCR_LOAD_ANIM_FADE_ON:
+        case LV_SCR_LOAD_ANIM_FADE_IN:
             lv_anim_set_exec_cb(&a_new, opa_scale_anim);
             lv_anim_set_values(&a_new, LV_OPA_TRANSP, LV_OPA_COVER);
             break;
+        case LV_SCR_LOAD_ANIM_FADE_OUT:
+            lv_anim_set_exec_cb(&a_old, opa_scale_anim);
+            lv_anim_set_values(&a_old, LV_OPA_COVER, LV_OPA_TRANSP);
+            break;
+        case LV_SCR_LOAD_ANIM_OUT_LEFT:
+            lv_anim_set_exec_cb(&a_old, set_x_anim);
+            lv_anim_set_values(&a_old, 0, -lv_disp_get_hor_res(d));
+            break;
+        case LV_SCR_LOAD_ANIM_OUT_RIGHT:
+            lv_anim_set_exec_cb(&a_old, set_x_anim);
+            lv_anim_set_values(&a_old, 0, lv_disp_get_hor_res(d));
+            break;
+        case LV_SCR_LOAD_ANIM_OUT_TOP:
+            lv_anim_set_exec_cb(&a_old, set_y_anim);
+            lv_anim_set_values(&a_old, 0, -lv_disp_get_ver_res(d));
+            break;
+        case LV_SCR_LOAD_ANIM_OUT_BOTTOM:
+            lv_anim_set_exec_cb(&a_old, set_y_anim);
+            lv_anim_set_values(&a_old, 0, lv_disp_get_ver_res(d));
+            break;
     }
 
     lv_event_send(act_scr, LV_EVENT_SCREEN_UNLOAD_START, NULL);
@@ -449,6 +470,16 @@ static void scr_anim_ready(lv_anim_t * a)
 
     if(d->prev_scr && d->del_prev) lv_obj_del(d->prev_scr);
     d->prev_scr = NULL;
+    d->draw_prev_over_act = false;
     d->scr_to_load = NULL;
     lv_obj_remove_local_style_prop(a->var, LV_STYLE_OPA, 0);
 }
+
+static bool is_out_anim(lv_scr_load_anim_t anim_type)
+{
+    return anim_type == LV_SCR_LOAD_ANIM_FADE_OUT  ||
+           anim_type == LV_SCR_LOAD_ANIM_OUT_LEFT  ||
+           anim_type == LV_SCR_LOAD_ANIM_OUT_RIGHT ||
+           anim_type == LV_SCR_LOAD_ANIM_OUT_TOP   ||
+           anim_type == LV_SCR_LOAD_ANIM_OUT_BOTTOM;
+}

src/core/lv_disp.h

@@ -35,7 +35,13 @@ typedef enum {
     LV_SCR_LOAD_ANIM_MOVE_RIGHT,
     LV_SCR_LOAD_ANIM_MOVE_TOP,
     LV_SCR_LOAD_ANIM_MOVE_BOTTOM,
-    LV_SCR_LOAD_ANIM_FADE_ON,
+    LV_SCR_LOAD_ANIM_FADE_IN,
+    LV_SCR_LOAD_ANIM_FADE_ON = LV_SCR_LOAD_ANIM_FADE_IN, /*For backward compatibility*/
+    LV_SCR_LOAD_ANIM_FADE_OUT,
+    LV_SCR_LOAD_ANIM_OUT_LEFT,
+    LV_SCR_LOAD_ANIM_OUT_RIGHT,
+    LV_SCR_LOAD_ANIM_OUT_TOP,
+    LV_SCR_LOAD_ANIM_OUT_BOTTOM,
 } lv_scr_load_anim_t;
 
 /**********************

src/core/lv_indev.c

@@ -75,14 +75,15 @@ void lv_indev_read_timer_cb(lv_timer_t * timer)
     /*Handle reset query before processing the point*/
     indev_proc_reset_query_handler(indev_act);
 
-    if(indev_act->proc.disabled) return;
+    if(indev_act->proc.disabled ||
+       indev_act->driver->disp->prev_scr != NULL) return; /*Input disabled or screen animation active*/
     bool continue_reading;
     do {
         /*Read the data*/
         _lv_indev_read(indev_act, &data);
         continue_reading = data.continue_reading;
 
-        /*The active object might deleted even in the read function*/
+        /*The active object might be deleted even in the read function*/
         indev_proc_reset_query_handler(indev_act);
         indev_obj_act = NULL;
 

src/core/lv_indev.h

@@ -35,7 +35,11 @@ extern "C" {
  */
 void lv_indev_read_timer_cb(lv_timer_t * timer);
 
-
+/**
+ * Enable or disable an input device (default enabled)
+ * @param indev pointer to an input device
+ * @param en true to enable, false to disable
+ */
 void lv_indev_enable(lv_indev_t * indev, bool en);
 
 /**

src/core/lv_refr.c

@@ -668,14 +668,27 @@ static void lv_refr_area_part(lv_draw_ctx_t * draw_ctx)
             lv_draw_rect(draw_ctx, &dsc, draw_ctx->buf_area);
         }
     }
-    /*Refresh the previous screen if any*/
-    if(disp_refr->prev_scr) {
-        if(top_prev_scr == NULL) top_prev_scr = disp_refr->prev_scr;
-        lv_refr_obj_and_children(draw_ctx, top_prev_scr);
-    }
 
-    if(top_act_scr == NULL) top_act_scr = disp_refr->act_scr;
-    lv_refr_obj_and_children(draw_ctx, top_act_scr);
+    if(disp_refr->draw_prev_over_act) {
+        if(top_act_scr == NULL) top_act_scr = disp_refr->act_scr;
+        lv_refr_obj_and_children(draw_ctx, top_act_scr);
+
+        /*Refresh the previous screen if any*/
+        if(disp_refr->prev_scr) {
+            if(top_prev_scr == NULL) top_prev_scr = disp_refr->prev_scr;
+            lv_refr_obj_and_children(draw_ctx, top_prev_scr);
+        }
+    }
+    else {
+        /*Refresh the previous screen if any*/
+        if(disp_refr->prev_scr) {
+            if(top_prev_scr == NULL) top_prev_scr = disp_refr->prev_scr;
+            lv_refr_obj_and_children(draw_ctx, top_prev_scr);
+        }
+
+        if(top_act_scr == NULL) top_act_scr = disp_refr->act_scr;
+        lv_refr_obj_and_children(draw_ctx, top_act_scr);
+    }
 
     /*Also refresh top and sys layer unconditionally*/
     lv_refr_obj_and_children(draw_ctx, lv_disp_get_layer_top(disp_refr));

src/hal/lv_hal_disp.h

@@ -170,6 +170,8 @@ typedef struct _lv_disp_t {
     struct _lv_obj_t * top_layer;   /**< @see lv_disp_get_layer_top*/
     struct _lv_obj_t * sys_layer;   /**< @see lv_disp_get_layer_sys*/
     uint32_t screen_cnt;
+uint8_t draw_prev_over_act  :
+    1;          /**< 1: Draw previous screen over active screen*/
 uint8_t del_prev  :
     1;          /**< 1: Automatically delete the previous screen when the screen load animation is ready*/
     uint8_t rendering_in_progress : 1; /**< 1: The current screen rendering is in progress*/