add move frame buttons

data/dialogs/panel-animation.xml

@@ -57,6 +57,12 @@
         <button-custom id="btn-down" thickness="1" color="0 0" border-color=".0" shrink="1" margin="0 2 0 0">
           <icon width="30" icon="bullet_arrow_down"/>
         </button-custom>
+        <button-custom id="btn-left" thickness="1" color="0 0" border-color=".0" shrink="1" margin="0 2 0 0">
+          <icon width="30" icon="resultset_previous"/>
+        </button-custom>
+        <button-custom id="btn-right" thickness="1" color="0 0" border-color=".0" shrink="1" margin="0 2 0 0">
+          <icon width="30" icon="resultset_next"/>
+        </button-custom>
 
         <node grow="1" dir="row" justify="center">
           <border pad="5" align="center" margin="0 10 0 0" dir="row" color=".3">

src/canvas_layer.cpp

@@ -228,10 +228,11 @@ bool Layer::create(int width, int height, std::string name)
     return true;
 }
 
-bool Layer::add_frame()
+bool Layer::add_frame(int index /*= -1*/)
 {
-    m_frames.emplace_back();
+    auto pos = index == -1 ? m_frames.end() : m_frames.begin() + index;
-    m_frames.back().create(w, h);
+    auto it = m_frames.emplace(pos);
+    it->create(w, h);
     frames_gpu_update();
     return true;
 }
@@ -267,6 +268,21 @@ void Layer::frames_gpu_update()
     });
 }
 
+int Layer::move_frame_offset(int frame, int offset) noexcept
+{
+    int new_pos = glm::clamp(frame + offset, 0, (int)m_frames.size() - 1);
+    auto from = m_frames.begin() + frame;
+    auto to = m_frames.begin() + new_pos;
+
+    if (new_pos < frame)
+        std::rotate(to, from, from + 1);
+    if (new_pos > frame)
+        std::rotate(from, from + 1, to + 1);
+
+    frames_gpu_update();
+    return new_pos;
+}
+
 int Layer::total_duration() const noexcept
 {
     int duration = 0;

src/canvas_layer.h

@@ -69,13 +69,14 @@ public:
     LayerFrame& frame(int frame = -1);
     void resize(int width, int height);
     bool create(int width, int height, std::string name);
-    bool add_frame();
+    bool add_frame(int index = -1);
     void remove_frame(int frame);
     void duplicate_frame(int frame);
     void frames_gpu_update();
     int frames_count() const noexcept { return m_frames.size(); }
     int frame_duration(int frame) const noexcept { return m_frames[frame].m_duration; }
     void set_frame_duration(int frame, int duration) noexcept { m_frames[frame].m_duration = duration; }
+    int move_frame_offset(int frame, int offset) noexcept;
     int total_duration() const noexcept;
     void goto_frame(int frame) noexcept;
     void clear(const glm::vec4& c, int frame = -1);

src/node_panel_animation.cpp

@@ -33,6 +33,8 @@ void NodePanelAnimation::init_controls()
     btn_remove = find<NodeButtonCustom>("btn-remove");
     btn_up = find<NodeButtonCustom>("btn-up");
     btn_down = find<NodeButtonCustom>("btn-down");
+    btn_left = find<NodeButtonCustom>("btn-left");
+    btn_right = find<NodeButtonCustom>("btn-right");
     btn_duplicate = find<NodeButtonCustom>("btn-duplicate");
     btn_next = find<NodeButtonCustom>("btn-next");
     btn_prev = find<NodeButtonCustom>("btn-prev");
@@ -63,6 +65,22 @@ void NodePanelAnimation::init_controls()
             layer->set_frame_duration(m_selected_frame_index, glm::max(layer->frame_duration(m_selected_frame_index) - 1, 1));
         load_layers();
     };
+    btn_left->on_click = [this](Node*) {
+        if (!m_selected_frame)
+            return;
+        if (auto layer = Canvas::I->layer_with_id(m_selected_frame_layer_id))
+            m_selected_frame_index = layer->move_frame_offset(m_selected_frame_index, -1);
+        Canvas::I->anim_goto_frame(m_selected_frame_index);
+        load_layers();
+    };
+    btn_right->on_click = [this](Node*) {
+        if (!m_selected_frame)
+            return;
+        if (auto layer = Canvas::I->layer_with_id(m_selected_frame_layer_id))
+            m_selected_frame_index = layer->move_frame_offset(m_selected_frame_index, +1);
+        Canvas::I->anim_goto_frame(m_selected_frame_index);
+        load_layers();
+    };
 
     m_onion->on_select = [this] (Node* target, int index) {
         m_timeline->m_onion_size = m_onion->get_int();

src/node_panel_animation.h

@@ -52,6 +52,8 @@ class NodePanelAnimation : public Node
     NodeButtonCustom* btn_remove = nullptr;
     NodeButtonCustom* btn_up = nullptr;
     NodeButtonCustom* btn_down = nullptr;
+    NodeButtonCustom* btn_left = nullptr;
+    NodeButtonCustom* btn_right = nullptr;
     NodeButtonCustom* btn_duplicate = nullptr;
     Node* m_layers_container = nullptr;
     Node* m_frames_container = nullptr;