new keyboard code

src/main/java/de/mrbesen/telegram/objects/TInlineKeyboardMarkup.java

@@ -1,27 +1,31 @@
 package de.mrbesen.telegram.objects;
 
 import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
 
 import org.json.JSONArray;
 import org.json.JSONObject;
 
 public class TInlineKeyboardMarkup implements TReplyMarkup {
 
-	ArrayList<JSONArray> arr_btn = new ArrayList<>();
+	List<JSONArray> arr_btn;
 	
 	public TInlineKeyboardMarkup() {
 		this(1);
-	}	
-	
+	}
+
+	/**
+	 * @param rows is a hint, how many lines will be needed
+	 */
 	public TInlineKeyboardMarkup(int rows) {
-		if(rows < 1)
-			throw new IllegalArgumentException("You need at least one row.");
-		arr_btn = new ArrayList<JSONArray>();
-		
-		for( int row = 0; row < rows; row++ ) {
-			arr_btn.add(new JSONArray());
+		arr_btn = new ArrayList<>(rows);
+
+		for(int row = 0; row < rows; ++row) {
+			arr_btn.add(row, new JSONArray());
 		}
 	}
+
 	/**
 	 * Insert button in first line
 	 * @param title
@@ -36,19 +40,43 @@ public class TInlineKeyboardMarkup implements TReplyMarkup {
 	 * Insert button in nth line
 	 * @param title
 	 * @param url
-	 * @param row
+	 * @param row (1 indexed)
 	 * @return
 	 */
 	public TInlineKeyboardMarkup addUrlButton(String title, String url, int row) {
-		arr_btn.get(row-1).put(new JSONObject().put("text", title).put("url", url));
+		addButton(row, new JSONObject().put("text", title).put("url", url));
 		return this;
 	}
-	
+
+	/**
+	 * insert button in nth line
+	 * @param title
+	 * @param callback
+	 * @param row (1 indexed)
+	 * @return
+	 */
 	public TInlineKeyboardMarkup addCallbackButton(String title, String callback, int row) {
-		arr_btn.get(row-1).put(new JSONObject().put("text", title).put("callback_data", callback));
+		addButton(row, new JSONObject().put("text", title).put("callback_data", callback));
 		return this;
 	}
 
+	/**
+	 * Add a button, check if the row is available first
+	 * @param row
+	 * @param btn
+	 */
+	private void addButton(int row, JSONObject btn) {
+		--row;
+		if(arr_btn.size() < row) {
+			//row existiert noch nicht
+			row = arr_btn.size(); //auf nächst größte Zeile setzten, damit keine leerzeilen entstehen
+			//resize
+			arr_btn.add(row, new JSONArray());
+		}
+		JSONArray arr = arr_btn.get(row);
+		arr.put(btn);
+	}
+
 	public static TInlineKeyboardMarkup makeYesNo(String yes, String no) {
 		return makeYesNo(yes, no, "");
 	}
@@ -69,6 +97,7 @@ public class TInlineKeyboardMarkup implements TReplyMarkup {
 	
 	@Override
 	public String toJSONString() {
+		arr_btn.removeIf(a -> a.isEmpty()); //remove empty rows
 		return new JSONObject().put("inline_keyboard", new JSONArray(arr_btn)).toString();
 	}
 }