Add ImGuiStorage

imgui-binding/src/main/java/imgui/ImGuiStorage.java

@@ -0,0 +1,114 @@
+package imgui;
+
+/**
+ * Helper: Key-Value storage
+ * Typically you don't have to worry about this since a storage is held within each Window.
+ * We use it to e.g. store collapse state for a tree (Int 0/1)
+ * This is optimized for efficient lookup (dichotomy into a contiguous buffer) and rare insertion (typically tied to user interactions aka max once a frame)
+ * You can use it as custom user storage for temporary values. Declare your own storage if, for example:
+ * - You want to manipulate the open/close state of a particular sub-tree in your interface (tree node uses Int 0/1 to store their state).
+ * - You want to store custom debug data easily without adding or editing structures in your code (probably not efficient, but convenient)
+ * Types are NOT stored, so it is up to you to make sure your Key don't collide with different types.
+ */
+public final class ImGuiStorage implements ImGuiDestroyableStruct {
+    long ptr;
+
+    /**
+     * This class will create a native structure.
+     * Call {@link #destroy()} method to manually free used memory.
+     */
+    public ImGuiStorage() {
+        ImGui.touch();
+        ptr = nCreate();
+    }
+
+    ImGuiStorage(final long ptr) {
+        this.ptr = ptr;
+    }
+
+    @Override
+    public void destroy() {
+        nDestroy(ptr);
+    }
+
+    /*JNI
+        #include <stdint.h>
+        #include <imgui.h>
+
+        jfieldID imGuiStoragePtrID;
+
+        #define IMGUI_STORAGE ((ImGuiStorage*)env->GetLongField(object, imGuiStoragePtrID))
+     */
+
+    static native void nInit(); /*
+        jclass jImGuiStorageClass = env->FindClass("imgui/ImGuiStorage");
+        imGuiStoragePtrID = env->GetFieldID(jImGuiStorageClass, "ptr", "J");
+    */
+
+    private native long nCreate(); /*
+        ImGuiStorage* imGuiStorage = new ImGuiStorage();
+        return (intptr_t)imGuiStorage;
+    */
+
+    private native void nDestroy(long ptr); /*
+        delete (ImGuiStorage*)ptr;
+    */
+
+    // - Get***() functions find pair, never add/allocate. Pairs are sorted so a query is O(log N)
+    // - Set***() functions find pair, insertion on demand if missing.
+    // - Sorted insertion is costly, paid once. A typical frame shouldn't need to insert any new pair.
+
+    public native void clear(); /*
+        IMGUI_STORAGE->Clear();
+    */
+
+    public native int getInt(int imGuiID); /*
+        return IMGUI_STORAGE->GetInt(imGuiID);
+    */
+
+    public native int getInt(int imGuiID, int defaultVal); /*
+        return IMGUI_STORAGE->GetInt(imGuiID, defaultVal);
+    */
+
+    public native void setInt(int imGuiID, int val); /*
+        IMGUI_STORAGE->SetInt(imGuiID, val);
+    */
+
+    public native boolean getBool(int imGuiID); /*
+        return IMGUI_STORAGE->GetBool(imGuiID);
+    */
+
+    public native boolean getBool(int imGuiID, boolean defaultVal); /*
+        return IMGUI_STORAGE->GetBool(imGuiID, defaultVal);
+    */
+
+    public native void setBool(int imGuiID, boolean val); /*
+        IMGUI_STORAGE->SetBool(imGuiID, val);
+    */
+
+    public native float getFloat(int imGuiID); /*
+        return IMGUI_STORAGE->GetFloat(imGuiID);
+    */
+
+    public native float getFloat(int imGuiID, float defaultVal); /*
+        return IMGUI_STORAGE->GetFloat(imGuiID, defaultVal);
+    */
+
+    public native void setFloat(int imGuiID, float val); /*
+        IMGUI_STORAGE->SetFloat(imGuiID, val);
+    */
+
+    /**
+     * Use on your own storage if you know only integer are being stored (open/close all tree nodes)
+     */
+    public native void setAllInt(int val); /*
+        IMGUI_STORAGE->SetAllInt(val);
+    */
+
+    /**
+     * For quicker full rebuild of a storage (instead of an incremental one), you may add all your contents and then sort once.
+     */
+    public native void buildSortByKey(); /*
+        IMGUI_STORAGE->BuildSortByKey();
+    */
+}