Update tree camera and scrollbar dragging every frame (#1087)

src/main/java/codechicken/nei/bookmark/tree/Camera.java

@@ -2,6 +2,8 @@ package codechicken.nei.bookmark.tree;
 
 import java.awt.geom.Point2D;
 
+import org.lwjgl.input.Mouse;
+
 class Camera {
 
     private static final float ZOOM_MIN = 0.1f;
@@ -39,23 +41,34 @@ class Camera {
                 && y < this.widgetY + this.widgetH;
     }
 
-    public void startDrag(int mouseX, int mouseY) {
+    public void startDrag(Point2D mouse) {
         this.dragging = true;
-        this.lastDragX = mouseX;
-        this.lastDragY = mouseY;
+        this.lastDragX = (float) mouse.getX();
+        this.lastDragY = (float) mouse.getY();
     }
 
-    public void drag(int mouseX, int mouseY) {
+    public void drag(Point2D mouse) {
         if (!this.dragging) {
             return;
         }
 
+        final float mouseX = (float) mouse.getX();
+        final float mouseY = (float) mouse.getY();
+
         this.scrollX -= (mouseX - this.lastDragX) / this.zoomLevel;
         this.scrollY -= (mouseY - this.lastDragY) / this.zoomLevel;
         this.lastDragX = mouseX;
         this.lastDragY = mouseY;
     }
 
+    public void update(Point2D mouse, int treeWidth, int treeHeight) {
+        if (this.dragging && Mouse.isButtonDown(0)) {
+            drag(mouse);
+        }
+
+        clampToBounds(treeWidth, treeHeight);
+    }
+
     public void endDrag() {
         this.dragging = false;
     }
@@ -79,7 +92,6 @@ class Camera {
         } else {
             this.scrollY -= direction * this.widgetH / (SCROLL_STEP_DIVISOR * this.zoomLevel);
         }
-
     }
 
     public void centerOn(float worldX, float worldY) {

src/main/java/codechicken/nei/bookmark/tree/CraftingTreeCanvas.java

@@ -169,12 +169,12 @@ class CraftingTreeCanvas {
                 : -FIT_MARGIN;
     }
 
-    public void startDrag(int mouseX, int mouseY) {
-        this.camera.startDrag(mouseX, mouseY);
+    public void startDrag(Point2D mouse) {
+        this.camera.startDrag(mouse);
     }
 
-    public void drag(int mouseX, int mouseY) {
-        this.camera.drag(mouseX, mouseY);
+    public void drag(Point2D mouse) {
+        this.camera.drag(mouse);
     }
 
     public void endDrag() {
@@ -259,7 +259,7 @@ class CraftingTreeCanvas {
 
     public void draw(Point2D mouse, Set<BookmarkItem> collapsedItems, SearchResult searchResult,
             boolean useInventorySnapshot, ItemTreeSlot hoveredNode, ItemTreeSlot deleteHoverNode) {
-        this.camera.clampToBounds(this.treeWidth, this.treeHeight);
+        this.camera.update(mouse, this.treeWidth, this.treeHeight);
 
         final float zScrollX = this.camera.scrollX * this.camera.zoomLevel;
         final float zScrollY = this.camera.scrollY * this.camera.zoomLevel;

src/main/java/codechicken/nei/bookmark/tree/GuiCraftingTree.java

@@ -757,7 +757,7 @@ public class GuiCraftingTree extends GuiContainer implements INEIGuiHandler, IGu
                 return true;
             }
 
-            this.canvas.startDrag(mouseX, mouseY);
+            this.canvas.startDrag(getMousePosition());
         }
 
         return false;
@@ -778,7 +778,7 @@ public class GuiCraftingTree extends GuiContainer implements INEIGuiHandler, IGu
 
         }
 
-        this.canvas.drag(mouseX, mouseY);
+        this.canvas.drag(getMousePosition());
     }
 
     @Override

src/main/java/codechicken/nei/scroll/ScrollContainer.java

@@ -7,6 +7,7 @@ import java.util.Map;
 import java.util.function.Predicate;
 
 import org.lwjgl.input.Keyboard;
+import org.lwjgl.input.Mouse;
 import org.lwjgl.opengl.GL11;
 
 import codechicken.lib.gui.GuiDraw;
@@ -249,6 +250,8 @@ public class ScrollContainer extends WidgetContainer {
         final boolean canScrollHorizontal = canScrollHorizontal();
 
         if (canScrollVertical || canScrollHorizontal) {
+            dragScrollBars(mousex, mousey, canScrollVertical, canScrollHorizontal);
+
             GuiHelper.useScissor(
                     this.x + this.paddingInlineStart,
                     this.y + this.paddingBlockStart,
@@ -273,6 +276,20 @@ public class ScrollContainer extends WidgetContainer {
 
     }
 
+    private void dragScrollBars(int mousex, int mousey, boolean canScrollVertical, boolean canScrollHorizontal) {
+        if (!Mouse.isButtonDown(0)) {
+            return;
+        }
+
+        if (canScrollVertical) {
+            this.verticalScrollBar.onMouseDragged(this, mousex, mousey, 0, 0);
+        }
+
+        if (canScrollHorizontal) {
+            this.horizontalScrollBar.onMouseDragged(this, mousex, mousey, 0, 0);
+        }
+    }
+
     protected void drawContent(int mousex, int mousey) {
         GL11.glPushAttrib(GL11.GL_ALL_ATTRIB_BITS);
         GL11.glPushMatrix();