[API] Implement binding for ImGui::getWindowScrollbarRect (#81)

* Implemented binding for ImGui::getWindowScrollbarRect

* checkstyle fixes

* more logic naming for boolean fields in ImGuiWindow struct

Co-authored-by: aleksandr.cayun <aleksandr.cayun@vizor-games.com>

imgui-binding/src/main/java/imgui/internal/ImGui.java

@@ -7,6 +7,8 @@
 public final class ImGui extends imgui.ImGui {
     private static final ImGuiDockNode DOCK_NODE = new ImGuiDockNode(0);
 
+    private static final ImGuiWindow IMGUI_CURRENT_WINDOW = new ImGuiWindow(0);
+
     /*JNI
         #include "_common.h"
         #include <imgui_internal.h>
@@ -172,4 +174,25 @@ public static boolean splitterBehavior(float bbMinX, float bbMinY, float bbMaxX,
     private static native boolean nSplitterBehaviour(float bbMinX, float bbMinY, float bbMaxX, float bbMaxY, int id, int imGuiAxis, float[] size1, float[] size2, float minSize1, float minSize2, float hoverExtend, float hoverVisibilityDelay); /*
         return ImGui::SplitterBehavior(ImRect(bbMinX, bbMinY, bbMaxX, bbMaxY), id, (ImGuiAxis)imGuiAxis, &size1[0], &size2[0], minSize1, minSize2, hoverExtend, hoverVisibilityDelay);
     */
+
+    public static ImGuiWindow getCurrentWindow() {
+        IMGUI_CURRENT_WINDOW.ptr = nGetCurrentWindow();
+        return IMGUI_CURRENT_WINDOW;
+    }
+
+    private static native long nGetCurrentWindow(); /*
+        return (intptr_t)ImGui::GetCurrentWindow();
+    */
+
+    public static ImRect getWindowScrollbarRect(final ImGuiWindow imGuiWindow, int axis) {
+        final ImRect imRect = new ImRect();
+        nGetWindowScrollbarRect(imGuiWindow.ptr, axis, imRect.min, imRect.max);
+        return imRect;
+    }
+
+    private static native void nGetWindowScrollbarRect(long windowPtr, int axis, ImVec2 minDstImVec2, ImVec2 maxDstImVec2); /*
+        ImRect rect = ImGui::GetWindowScrollbarRect((ImGuiWindow*)windowPtr, static_cast<ImGuiAxis>(axis));
+        Jni::ImVec2Cpy(env, &rect.Min, minDstImVec2);
+        Jni::ImVec2Cpy(env, &rect.Max, maxDstImVec2);
+    */
 }

imgui-binding/src/main/java/imgui/internal/ImGuiWindow.java

@@ -0,0 +1,31 @@
+package imgui.internal;
+
+import imgui.binding.ImGuiStruct;
+
+public class ImGuiWindow extends ImGuiStruct {
+    public ImGuiWindow(final long ptr) {
+        super(ptr);
+    }
+
+    /*JNI
+        #include "_common.h"
+        #include <imgui_internal.h>
+
+        #define IMGUI_WINDOW ((ImGuiWindow*)STRUCT_PTR)
+     */
+
+    /**
+     * Is scrollbar visible?
+     */
+    public native boolean isScrollbarX(); /*
+       return IMGUI_WINDOW->ScrollbarX;
+    */
+
+    /**
+     * Is scrollbar visible?
+     */
+    public native boolean isScrollbarY(); /*
+       return IMGUI_WINDOW->ScrollbarY;
+    */
+
+}