feat(gui): add zoom in/out actions (#1403)

jadx-gui/src/main/java/jadx/gui/ui/codearea/AbstractCodeArea.java

@@ -40,6 +40,7 @@ import jadx.gui.utils.DefaultPopupMenuListener;
 import jadx.gui.utils.JumpPosition;
 import jadx.gui.utils.NLS;
 import jadx.gui.utils.UiUtils;
+import jadx.gui.utils.ui.ZoomActions;
 
 public abstract class AbstractCodeArea extends RSyntaxTextArea {
 	private static final long serialVersionUID = -3980354865216031972L;
@@ -67,6 +68,8 @@ public abstract class AbstractCodeArea extends RSyntaxTextArea {
 
 		addCaretActions();
 		addFastCopyAction();
+
+		ZoomActions.register(this, settings, this::loadSettings);
 	}
 
 	private void addWrapLineMenuAction(JadxSettings settings) {

jadx-gui/src/main/java/jadx/gui/ui/panel/HtmlPanel.java

@@ -11,6 +11,7 @@ import javax.swing.JScrollPane;
 import jadx.gui.settings.JadxSettings;
 import jadx.gui.treemodel.JNode;
 import jadx.gui.ui.TabbedPane;
+import jadx.gui.utils.ui.ZoomActions;
 
 public final class HtmlPanel extends ContentPanel {
 	private static final long serialVersionUID = -6251262855835426245L;
@@ -27,6 +28,8 @@ public final class HtmlPanel extends ContentPanel {
 		textArea.setEditable(false);
 		JScrollPane sp = new JScrollPane(textArea);
 		add(sp);
+
+		ZoomActions.register(textArea, panel.getMainWindow().getSettings(), this::loadSettings);
 	}
 
 	@Override

jadx-gui/src/main/java/jadx/gui/utils/FontUtils.java

@@ -42,6 +42,9 @@ public class FontUtils {
 	}
 
 	public static String convertToStr(Font font) {
+		if (font.getSize() < 1) {
+			throw new JadxRuntimeException("Bad font size: " + font.getSize());
+		}
 		return font.getFontName()
 				+ '/' + convertFontStyleToString(font.getStyle())
 				+ '/' + font.getSize();

jadx-gui/src/main/java/jadx/gui/utils/ui/ActionHandler.java

+package jadx.gui.utils.ui;
+
+import java.awt.event.ActionEvent;
+import java.util.function.Consumer;
+
+import javax.swing.AbstractAction;
+
+public class ActionHandler extends AbstractAction {
+
+	private final Consumer<ActionEvent> consumer;
+
+	public ActionHandler(Consumer<ActionEvent> consumer) {
+		this.consumer = consumer;
+	}
+
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		consumer.accept(e);
+	}
+}

jadx-gui/src/main/java/jadx/gui/utils/ui/ZoomActions.java

+package jadx.gui.utils.ui;
+
+import java.awt.Container;
+import java.awt.Font;
+import java.awt.event.KeyEvent;
+
+import javax.swing.ActionMap;
+import javax.swing.InputMap;
+import javax.swing.JComponent;
+import javax.swing.KeyStroke;
+
+import jadx.gui.settings.JadxSettings;
+import jadx.gui.utils.UiUtils;
+
+public class ZoomActions {
+	private final JComponent component;
+	private final JadxSettings settings;
+	private final Runnable update;
+
+	public static void register(JComponent component, JadxSettings settings, Runnable update) {
+		ZoomActions actions = new ZoomActions(component, settings, update);
+		actions.register();
+	}
+
+	private ZoomActions(JComponent component, JadxSettings settings, Runnable update) {
+		this.component = component;
+		this.settings = settings;
+		this.update = update;
+	}
+
+	private void register() {
+		String zoomIn = "TextZoomIn";
+		String zoomOut = "TextZoomOut";
+		int ctrlButton = UiUtils.ctrlButton();
+		InputMap inputMap = component.getInputMap();
+		inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_PLUS, ctrlButton), zoomIn);
+		inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_EQUALS, ctrlButton), zoomIn);
+		inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_ADD, ctrlButton), zoomIn);
+		inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_MINUS, ctrlButton), zoomOut);
+		inputMap.put(KeyStroke.getKeyStroke(KeyEvent.VK_SUBTRACT, ctrlButton), zoomOut);
+		ActionMap actionMap = component.getActionMap();
+		actionMap.put(zoomIn, new ActionHandler(e -> textZoom(1)));
+		actionMap.put(zoomOut, new ActionHandler(e -> textZoom(-1)));
+
+		component.addMouseWheelListener(e -> {
+			if (e.getModifiersEx() == UiUtils.ctrlButton()) {
+				textZoom(e.getWheelRotation() < 0 ? 1 : -1);
+				e.consume();
+			} else {
+				// pass event to parent component, needed for scroll in JScrollPane
+				Container parent = component.getParent();
+				if (parent != null) {
+					parent.dispatchEvent(e);
+				}
+			}
+		});
+	}
+
+	private void textZoom(int change) {
+		Font font = settings.getFont();
+		if (component.getFont().equals(font)) {
+			settings.setFont(changeFontSize(font, change));
+		} else {
+			settings.setSmaliFont(changeFontSize(settings.getSmaliFont(), change));
+		}
+		settings.sync();
+		update.run();
+	}
+
+	private Font changeFontSize(Font font, int change) {
+		float newSize = font.getSize() + change;
+		if (newSize < 2) {
+			// ignore change
+			return font;
+		}
+		return font.deriveFont(newSize);
+	}
+}