[API] Extend ImString to accept more objects to set string from

Also make getBytes method to use UTF-8 charset

example/src/main/java/Main.java

@@ -46,6 +46,7 @@ public class Main extends Application {
         ImGui.sameLine();
         ImGui.text(String.valueOf(count));
         ImGui.inputText("string", str, ImGuiInputTextFlags.CallbackResize);
+        ImGui.text("Result: " + str.get());
         ImGui.sliderFloat("float", flt, 0, 1);
         ImGui.separator();
         ImGui.text("Extra");

imgui-binding/src/main/java/imgui/type/ImString.java

@@ -81,8 +81,16 @@ public final class ImString implements Cloneable {
         return data;
     }
 
+    public void set(final Object object) {
+        set(String.valueOf(object));
+    }
+
     public void set(final ImString value) {
-        set(value.get());
+        set(value.get(), true);
+    }
+
+    public void set(final ImString value, final boolean resize) {
+        set(value.get(), resize);
     }
 
     public void set(final String value) {
@@ -94,17 +102,17 @@ public final class ImString implements Cloneable {
     }
 
     public void set(final String value, final boolean resize, final int resizeValue) {
-        final byte[] valueBuff = (value == null ? "null" : value).getBytes();
+        final byte[] valueBuff = (value == null ? "null" : value).getBytes(StandardCharsets.UTF_8);
         final int currentLen = data == null ? 0 : data.length;
         byte[] newBuff = null;
 
-        // If provided value require a bigger buffer and we can resize it
+        // If provided value requires a bigger buffer and we can resize it
         if (resize && (currentLen - CARET_LEN) < valueBuff.length) {
             newBuff = new byte[valueBuff.length + resizeValue + CARET_LEN];
             inputData.size = valueBuff.length;
         }
 
-        // If there were no resize and we still need a new buffer
+        // If there was no resize, so we still need a new buffer
         if (newBuff == null) {
             newBuff = new byte[currentLen];
             inputData.size = Math.max(0, Math.min(valueBuff.length, currentLen - CARET_LEN));

imgui-binding/src/test/java/imgui/ImStringTest.java

@@ -32,28 +32,60 @@ class ImStringTest {
     }
 
     @Test
-    public void testSet() {
+    public void testSetWhenEmpty() {
         final ImString str = new ImString(3);
         assertEquals("", str.get());
         assertEquals(0, str.getLength());
         assertEquals(3 + 1, str.getBufferSize());
+    }
 
+    @Test
+    public void testSetWhenNotResized() {
+        final ImString str = new ImString(3);
         str.set("test");
         assertEquals("tes", str.get());
         assertEquals(3, str.getLength());
         assertEquals(3 + 1, str.getBufferSize());
+    }
 
+    @Test
+    public void testSetWhenResizedWithZeroResizeValue() {
+        final ImString str = new ImString(3);
         str.set("test", true, 0);
         assertEquals("test", str.get());
         assertEquals(4, str.getLength());
         assertEquals(4 + 1, str.getBufferSize());
+    }
 
+    @Test
+    public void testSetWhenResized() {
+        final ImString str = new ImString(3);
         str.set("0123456789", true);
         assertEquals("0123456789", str.get());
         assertEquals(10, str.getLength());
         assertEquals(10 + str.inputData.resizeFactor + 1, str.getBufferSize());
+    }
 
-        str.set(null);
+    @Test
+    public void testSetWhenNullObject() {
+        final ImString str = new ImString();
+        final Object object = null;
+        str.set(object);
         assertEquals("null", str.get());
     }
+
+    @Test
+    public void testSetWhenImString() {
+        final ImString str = new ImString();
+        final ImString string = new ImString("test");
+        str.set(string);
+        assertEquals("test", str.get());
+    }
+
+    @Test
+    public void testSetWhenNumber() {
+        final ImString str = new ImString();
+        str.set(123);
+        assertEquals("123", str.get());
+    }
 }