Add InputTextWithHint overloads

Author: Florian Maunier

src/ImGui.NET/ImGui.Manual.cs

@@ -247,6 +247,114 @@ public static bool InputTextMultiline(
             return result != 0;
         }
 
+        public static bool InputTextWithHint(
+            string label,
+            string hint,
+            ref string input,
+            uint maxLength) => InputTextWithHint(label, hint, ref input, maxLength, 0, null, IntPtr.Zero);
+
+        public static bool InputTextWithHint(
+            string label,
+            string hint,
+            ref string input,
+            uint maxLength,
+            ImGuiInputTextFlags flags) => InputTextWithHint(label, hint, ref input, maxLength, flags, null, IntPtr.Zero);
+
+        public static bool InputTextWithHint(
+            string label,
+            string hint,
+            ref string input,
+            uint maxLength,
+            ImGuiInputTextFlags flags,
+            ImGuiInputTextCallback callback) => InputTextWithHint(label, hint, ref input, maxLength, flags, callback, IntPtr.Zero);
+
+        public static bool InputTextWithHint(
+            string label,
+            string hint,
+            ref string input,
+            uint maxLength,
+            ImGuiInputTextFlags flags,
+            ImGuiInputTextCallback callback,
+            IntPtr user_data)
+        {
+            int utf8LabelByteCount = Encoding.UTF8.GetByteCount(label);
+            byte* utf8LabelBytes;
+            if (utf8LabelByteCount > Util.StackAllocationSizeLimit)
+            {
+                utf8LabelBytes = Util.Allocate(utf8LabelByteCount + 1);
+            }
+            else
+            {
+                byte* stackPtr = stackalloc byte[utf8LabelByteCount + 1];
+                utf8LabelBytes = stackPtr;
+            }
+            Util.GetUtf8(label, utf8LabelBytes, utf8LabelByteCount);
+
+            int utf8HintByteCount = Encoding.UTF8.GetByteCount(hint);
+            byte* utf8HintBytes;
+            if (utf8HintByteCount > Util.StackAllocationSizeLimit)
+            {
+                utf8HintBytes = Util.Allocate(utf8HintByteCount + 1);
+            }
+            else
+            {
+                byte* stackPtr = stackalloc byte[utf8HintByteCount + 1];
+                utf8HintBytes = stackPtr;
+            }
+            Util.GetUtf8(hint, utf8HintBytes, utf8HintByteCount);
+
+            int utf8InputByteCount = Encoding.UTF8.GetByteCount(input);
+            int inputBufSize = Math.Max((int)maxLength + 1, utf8InputByteCount + 1);
+
+            byte* utf8InputBytes;
+            byte* originalUtf8InputBytes;
+            if (inputBufSize > Util.StackAllocationSizeLimit)
+            {
+                utf8InputBytes = Util.Allocate(inputBufSize);
+                originalUtf8InputBytes = Util.Allocate(inputBufSize);
+            }
+            else
+            {
+                byte* inputStackBytes = stackalloc byte[inputBufSize];
+                utf8InputBytes = inputStackBytes;
+                byte* originalInputStackBytes = stackalloc byte[inputBufSize];
+                originalUtf8InputBytes = originalInputStackBytes;
+            }
+            Util.GetUtf8(input, utf8InputBytes, inputBufSize);
+            uint clearBytesCount = (uint)(inputBufSize - utf8InputByteCount);
+            Unsafe.InitBlockUnaligned(utf8InputBytes + utf8InputByteCount, 0, clearBytesCount);
+            Unsafe.CopyBlock(originalUtf8InputBytes, utf8InputBytes, (uint)inputBufSize);
+
+            byte result = ImGuiNative.igInputTextWithHint(
+                utf8LabelBytes,
+                utf8HintBytes,
+                utf8InputBytes,
+                (uint)inputBufSize,
+                flags,
+                callback,
+                user_data.ToPointer());
+            if (!Util.AreStringsEqual(originalUtf8InputBytes, inputBufSize, utf8InputBytes))
+            {
+                input = Util.StringFromPtr(utf8InputBytes);
+            }
+
+            if (utf8LabelByteCount > Util.StackAllocationSizeLimit)
+            {
+                Util.Free(utf8LabelBytes);
+            }
+            if (utf8HintByteCount > Util.StackAllocationSizeLimit)
+            {
+                Util.Free(utf8HintBytes);
+            }
+            if (inputBufSize > Util.StackAllocationSizeLimit)
+            {
+                Util.Free(utf8InputBytes);
+                Util.Free(originalUtf8InputBytes);
+            }
+
+            return result != 0;
+        }
+
         public static bool InputText(
             string label,
             IntPtr buf,