Resizing of Arc in Animation

How-to
1

It is possible to resize an Arc during an animation?

The only thing I have managed to do is moving an arc even though i use the lv_obj_set_width, not the lv_obj_set_x.

If I try using both an lv_obj_set_width and lv_obj_set_height in tow different animations at once, it crashed.

And if I try the lv_obj_set_size the arc disappears.

2

Please fill out the template.

1 Like
3

Description

It is possible to resize an Arc during an animation?

The only thing I have managed to do is moving an arc even though i use the lv_obj_set_width, not the lv_obj_set_x.

If I try using both an lv_obj_set_width and lv_obj_set_height in tow different animations at once, it crashed.

And if I try the lv_obj_set_size the arc disappears.

What MCU/Processor/Board and compiler are you using?

Pc Simulator on a Linux VMWare

What do you want to achieve?

Animation where an arc is enlarged on click

What have you tried so far?

See Description.

Code to reproduce

static lv_obj_t * Arc;

static void event_handler(lv_obj_t * obj, lv_event_t event)
{
    if(event == LV_EVENT_PRESSED) {
        lv_anim_t a;
        a.var = Arc;
        a.start = 135;
        a.end = 265;
        a.exec_cb = (lv_anim_exec_xcb_t) lv_obj_set_width;
        a.path_cb = lv_anim_path_linear;
        a.ready_cb = NULL;
        a.act_time = 0;
        a.time = 500;
        a.playback = 0;
        a.playback_pause = 0;
        a.repeat = 0;
        a.repeat_pause = 0;
        lv_anim_create(&a);
}

Right now the button push is coming from a button obj that has nothing to do with the arc

{

    static lv_style_t ArcStyle;

    lv_style_copy(&ArcStyle,&lv_style_plain);
    ArcStyle.line.color = LV_COLOR_BITZER;
    ArcStyle.line.width = 8;

   Arc = lv_arc_create(lv_disp_get_scr_act(NULL), NULL);
   lv_obj_set_size(Arc,135,135);
   lv_arc_set_angles(Arc, 0, 360);
   lv_arc_set_style(Arc, LV_ARC_STYLE_MAIN, &ArcStyle);
}
4

You need to animate the height too:


           lv_anim_t a;
           a.var = Arc;
           a.start = 135;
           a.end = 265;
           a.exec_cb = (lv_anim_exec_xcb_t) lv_obj_set_width;
           a.path_cb = lv_anim_path_linear;
           a.ready_cb = NULL;
           a.act_time = 0;
           a.time = 500;
           a.playback = 0;
           a.playback_pause = 0;
           a.repeat = 0;
           a.repeat_pause = 0;
           lv_anim_create(&a);

           /*Use the same anim. data jsut change the width to height*/
           a.exec_cb = (lv_anim_exec_xcb_t) lv_obj_set_height;
           lv_anim_create(&a);
5

Thanks, that do work

I thought I should make animation A for one width and B for height, but that only got it to crash instead.

6

For the record can you copy the code which crashed? It might be useful for people to see the difference.

7

I am trying to incapsulate the code in C++ classes, to use in a project.

This makes it crash:

        LvAnimation WidthChange(Arc);

        WidthChange.AnimMode(TypeAnim::Width, PathAnim::Linear);
        WidthChange.SetMovement(Arc.GetWidth(), Arc.GetWidth() + 100);
        WidthChange.SetTiming(0, 500);
        WidthChange.Play();

        LvAnimation HeightChange(Arc);

        HeightChange.AnimMode(TypeAnim::Height, PathAnim::Linear);
        HeightChange.SetMovement(Arc.GetHeigth(),Arc.GetHeigth() + 100);
        HeightChange.SetTiming(0, 500);
        HeightChange.Play();

While this makes it work

        LvAnimation SizeChange(Arc);

        SizeChange.AnimMode(TypeAnim::Width, PathAnim::Linear);
        SizeChange.SetMovement(Arc.GetWidth(), Arc.GetWidth() + 100);
        SizeChange.SetTiming(0, 500);
        SizeChange.Play();

        SizeChange.AnimMode(TypeAnim::Height, PathAnim::Linear);
        SizeChange.Play();

Behind the scenes the following stuff is happening

LvAnimation::LvAnimation(GuiObject obj)
{
    this->LvAnim->var = obj.GetObject();
}

void LvAnimation::SetTiming(int16_t StartTime, uint16_t Duration)
{
    this->LvAnim->act_time = StartTime;
    this->LvAnim->time = Duration;
}

void LvAnimation::SetMovement(int16_t Start, int16_t Finish)
{
    this->LvAnim->start = Start;
    this->LvAnim->end = Finish;
}

void LvAnimation::Play()
{
    lv_anim_create(this->LvAnim);
}

void LvAnimation::AnimMode(int Type, int Path)
{
    AnimType(Type);
    AnimPath(Path);
}

void LvAnimation::AnimType(int mode)
{
    switch (mode) {
    case TypeAnim::Height:
    {
        this->LvAnim->exec_cb =  reinterpret_cast<lv_anim_exec_xcb_t>(lv_obj_set_height);
        break;
    }
    case TypeAnim::Width:
    {
         this->LvAnim->exec_cb = reinterpret_cast<lv_anim_exec_xcb_t>(lv_obj_set_width);
        break;
    }

case ... ....
    }
}

void LvAnimation::AnimPath(int path)
{
    switch (path) {

    case PathAnim::Linear:
    default:
    {
        this->LvAnim->path_cb = lv_anim_path_linear;
        break;
    }

case ...  ...

    }
}

´´´
8

Thank you. However, I can’t see why it crashes. It seems you are just setting the same values again for height animation.

9

Yes, And it seems that if I use specific numbers for my start or end width, instead of my getWidth command, it also breaks.

10

I found the problem:

I had defined the animation variable as the pointer to it, rather then just an animation variable

// Was
lv_anim_t * LvAnim;

// Shoud be 
lv_anim_t LvAnim;

Now I can set specific sizes

11

Great!
I could see it from this->LvAnim->var because it should be this->LvAnim.var.

12

Maybe it’s just a temporary bug. If you could wait for it to pass.

13

As @ThaBitzer mentioned, the issue was solved.