@Override
	public boolean execute() {
		Boolean val = true;
		try {
			List<Font> fonts = new ArrayList<Font>();
			for (int i = this.startFrom; i <= this.endAt; i++) {
				Font previousFont = this.document.getChildren().get(i)
						.getFont();
				Font newFont = new Font(previousFont.getName(),
						previousFont.getStyle(), previousFont.getSize() + 1);
				fonts.add(newFont);
			}

			this.document.updateFont(fonts, startFrom, endAt);
		} catch (Exception ex) {
			ex.printStackTrace();
			val = false;
		}

		return val;
	}