feat: improve FlatTabbedPaneUI (#314)

src/main/java/app/termora/MyFlatTabbedPaneUI.java

@@ -0,0 +1,139 @@
+package app.termora;
+
+import com.formdev.flatlaf.ui.FlatTabbedPaneUI;
+import com.formdev.flatlaf.ui.FlatUIUtils;
+
+import javax.swing.*;
+import java.awt.*;
+import java.awt.geom.Path2D;
+import java.awt.geom.Rectangle2D;
+
+import static com.formdev.flatlaf.FlatClientProperties.*;
+import static com.formdev.flatlaf.util.UIScale.scale;
+
+/**
+ * 如果要升级 FlatLaf 需要检查是否兼容
+ */
+public class MyFlatTabbedPaneUI extends FlatTabbedPaneUI {
+    @Override
+    protected void paintContentBorder(Graphics g, int tabPlacement, int selectedIndex) {
+        if (tabPane.getTabCount() <= 0 ||
+                contentSeparatorHeight == 0 ||
+                !clientPropertyBoolean(tabPane, TABBED_PANE_SHOW_CONTENT_SEPARATOR, showContentSeparator))
+            return;
+
+        Insets insets = tabPane.getInsets();
+        Insets tabAreaInsets = getTabAreaInsets(tabPlacement);
+
+        int x = insets.left;
+        int y = insets.top;
+        int w = tabPane.getWidth() - insets.right - insets.left;
+        int h = tabPane.getHeight() - insets.top - insets.bottom;
+
+        // remove tabs from bounds
+        switch (tabPlacement) {
+            case BOTTOM:
+                h -= calculateTabAreaHeight(tabPlacement, runCount, maxTabHeight);
+                h += tabAreaInsets.top;
+                break;
+
+            case LEFT:
+                x += calculateTabAreaWidth(tabPlacement, runCount, maxTabWidth);
+                x -= tabAreaInsets.right;
+                w -= (x - insets.left);
+                break;
+
+            case RIGHT:
+                w -= calculateTabAreaWidth(tabPlacement, runCount, maxTabWidth);
+                w += tabAreaInsets.left;
+                break;
+
+            case TOP:
+            default:
+                y += calculateTabAreaHeight(tabPlacement, runCount, maxTabHeight);
+                y -= tabAreaInsets.bottom;
+                h -= (y - insets.top);
+                break;
+        }
+
+        // compute insets for separator or full border
+        boolean hasFullBorder = clientPropertyBoolean(tabPane, TABBED_PANE_HAS_FULL_BORDER, this.hasFullBorder);
+        int sh = scale(contentSeparatorHeight * 100); // multiply by 100 because rotateInsets() does not use floats
+        Insets ci = new Insets(0, 0, 0, 0);
+        rotateInsets(hasFullBorder ? new Insets(sh, sh, sh, sh) : new Insets(sh, 0, 0, 0), ci, tabPlacement);
+
+        // create path for content separator or full border
+        Path2D path = new Path2D.Float(Path2D.WIND_EVEN_ODD);
+        path.append(new Rectangle2D.Float(x, y, w, h), false);
+        path.append(new Rectangle2D.Float(x + (ci.left / 100f), y + (ci.top / 100f),
+                w - (ci.left / 100f) - (ci.right / 100f), h - (ci.top / 100f) - (ci.bottom / 100f)), false);
+
+        // add gap for selected tab to path
+        if (getTabType() == TAB_TYPE_CARD && selectedIndex >= 0) {
+            float csh = scale((float) contentSeparatorHeight);
+
+            Rectangle tabRect = getTabBounds(tabPane, selectedIndex);
+            boolean componentHasFullBorder = false;
+            if (tabPane.getComponentAt(selectedIndex) instanceof JComponent c) {
+                componentHasFullBorder = c.getClientProperty(TABBED_PANE_HAS_FULL_BORDER) == Boolean.TRUE;
+            }
+            Rectangle2D.Float innerTabRect = new Rectangle2D.Float(tabRect.x + csh, tabRect.y + csh,
+                    componentHasFullBorder ? 0 : tabRect.width - (csh * 2), tabRect.height - (csh * 2));
+
+            // Ensure that the separator outside the tabViewport is present (doesn't get cutoff by the active tab)
+            // If left unsolved the active tab is "visible" in the separator (the gap) even when outside the viewport
+            if (tabViewport != null)
+                Rectangle2D.intersect(tabViewport.getBounds(), innerTabRect, innerTabRect);
+
+            Rectangle2D.Float gap = null;
+            if (isHorizontalTabPlacement(tabPlacement)) {
+                if (innerTabRect.width > 0) {
+                    float y2 = (tabPlacement == TOP) ? y : y + h - csh;
+                    gap = new Rectangle2D.Float(innerTabRect.x, y2, innerTabRect.width, csh);
+                }
+            } else {
+                if (innerTabRect.height > 0) {
+                    float x2 = (tabPlacement == LEFT) ? x : x + w - csh;
+                    gap = new Rectangle2D.Float(x2, innerTabRect.y, csh, innerTabRect.height);
+                }
+            }
+
+            if (gap != null) {
+                path.append(gap, false);
+
+                // fill gap in case that the tab is colored (e.g. focused or hover)
+                Color background = getTabBackground(tabPlacement, selectedIndex, true);
+                g.setColor(FlatUIUtils.deriveColor(background, tabPane.getBackground()));
+                ((Graphics2D) g).fill(gap);
+            }
+        }
+
+        // paint content separator or full border
+        g.setColor(contentAreaColor);
+        ((Graphics2D) g).fill(path);
+
+        // repaint selection in scroll-tab-layout because it may be painted before
+        // the content border was painted (from BasicTabbedPaneUI$ScrollableTabPanel)
+        if (isScrollTabLayout() && selectedIndex >= 0 && tabViewport != null) {
+            Rectangle tabRect = getTabBounds(tabPane, selectedIndex);
+
+            // clip to "scrolling sides" of viewport
+            // (left and right if horizontal, top and bottom if vertical)
+            Shape oldClip = g.getClip();
+            Rectangle vr = tabViewport.getBounds();
+            if (isHorizontalTabPlacement(tabPlacement))
+                g.clipRect(vr.x, 0, vr.width, tabPane.getHeight());
+            else
+                g.clipRect(0, vr.y, tabPane.getWidth(), vr.height);
+
+            paintTabSelection(g, tabPlacement, selectedIndex, tabRect.x, tabRect.y, tabRect.width, tabRect.height);
+            g.setClip(oldClip);
+        }
+    }
+
+
+    private boolean isScrollTabLayout() {
+        return tabPane.getTabLayoutPolicy() == JTabbedPane.SCROLL_TAB_LAYOUT;
+    }
+
+}

src/main/kotlin/app/termora/MyTabbedPane.kt

@@ -10,6 +10,7 @@ import java.awt.event.*
 import java.awt.image.BufferedImage
 import java.util.*
 import javax.swing.*
+import javax.swing.plaf.TabbedPaneUI
 import kotlin.math.abs
 
 class MyTabbedPane : FlatTabbedPane() {
@@ -21,12 +22,18 @@ class MyTabbedPane : FlatTabbedPane() {
     private val owner
         get() = AnActionEvent(this, StringUtils.EMPTY, EventObject(this))
             .getData(DataProviders.TermoraFrame) as TermoraFrame
+    private val myUI = MyFlatTabbedPaneUI()
 
     init {
         isFocusable = false
+        super.setUI(myUI)
         initEvents()
     }
 
+    override fun setUI(ui: TabbedPaneUI?) {
+        super.setUI(myUI)
+    }
+
     override fun updateUI() {
         styleMap = mapOf(
             "focusColor" to UIManager.getColor("TabbedPane.selectedBackground"),