Better best font size calculation (JAVAAPI-644)

SwingUtilities/src/main/java/fr/soleil/lib/project/swing/listener/DynamicFontSizeManager.java

@@ -280,8 +280,14 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
         if (frc != null) {
             textBounds = font.getStringBounds(text, frc);
         }
+        // Take account of maximum size only if programmatically set (JAVAAPI-644)
+        Dimension maxSize = (component == null) || (!component.isMaximumSizeSet()) ? null : component.getMaximumSize();
+        int maxWidth = maxSize == null ? 0 : maxSize.width;
+        if (borderAndIconMargin != null) {
+            maxWidth -= borderAndIconMargin.width;
+        }
         return computeBestFontSizeIgnoreHeight(component, font, text, fixedTextWidth, compWidth, textBounds,
-                borderAndIconMargin);
+                borderAndIconMargin, maxWidth);
     }
 
     /**
@@ -295,11 +301,12 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
      * @param textBounds The previously calculated text bounds.
      * @param borderAndIconMargin The previously calculated border and icon margin (using
      *            {@link #getBorderAndIconMargin(JComponent)}).
+     * @param knownMaxWidth The known maximum width for the component (already reduced by border and icon margin)
      * @return An <code>int</code>: the calculated best font size. <code>-1</code> if such a font size could not be
      *         calculated. You should avoid <code>0</code> too.
      */
     public static int computeBestFontSizeIgnoreHeight(Component component, Font font, String text, int fixedTextWidth,
-            int compWidth, Rectangle2D textBounds, Dimension borderAndIconMargin) {
+            int compWidth, Rectangle2D textBounds, Dimension borderAndIconMargin, int knownMaxWidth) {
         int fontSizeToUse;
         if (text == null || text.isEmpty()) {
             // No text found: no best font size.
@@ -307,21 +314,45 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
         } else {
             // Step 2: Recover component and font sizes.
             compWidth = getMaxAllowedWidth(component, borderAndIconMargin, compWidth);
-
-            int textWidth;
-            if (fixedTextWidth < 1) {
-                textWidth = getWidth(textBounds, component, font, text);
-            } else {
-                textWidth = fixedTextWidth;
-            }
+            int textWidth = fixedTextWidth < 1 ? getWidth(textBounds, component, font, text) : fixedTextWidth;
             // Step 3: Find out how much the font can grow in width.
             float widthRatio = getBestRatio((float) compWidth / (float) textWidth);
-
             fontSizeToUse = (int) Math.floor(font.getSize() * widthRatio);
+            // Step 4: Limit font size according to known maximum text width if it is > 0 (JAVAAPI-644)
+            if (knownMaxWidth > 0) {
+                int newWidth = textWidth * Math.round(fontSizeToUse / font.getSize2D());
+                if (newWidth > knownMaxWidth) {
+                    widthRatio = getBestRatio(knownMaxWidth / (float) newWidth);
+                    fontSizeToUse = Math.round(fontSizeToUse * widthRatio);
+                    if (fontSizeToUse == 0) {
+                        fontSizeToUse = -1;
+                    }
+                }
+            }
         }
         return fontSizeToUse;
     }
 
+    /**
+     * Computes the best {@link Font} size for a {@link Component}, according to given text.
+     * 
+     * @param component The {@link Component}.
+     * @param font The referent {@link Font}.
+     * @param text The text.
+     * @param fixedTextWidth The previously calculated text width. Use a value &gt; 0 to avoid calculating text width.
+     * @param compWidth The previously calculated component width. Use a value &ge; 0 to avoid asking component's width.
+     * @param textBounds The previously calculated text bounds.
+     * @param borderAndIconMargin The previously calculated border and icon margin (using
+     *            {@link #getBorderAndIconMargin(JComponent)}).
+     * @return An <code>int</code>: the calculated best font size. <code>-1</code> if such a font size could not be
+     *         calculated. You should avoid <code>0</code> too.
+     */
+    public static int computeBestFontSizeIgnoreHeight(Component component, Font font, String text, int fixedTextWidth,
+            int compWidth, Rectangle2D textBounds, Dimension borderAndIconMargin) {
+        return computeBestFontSizeIgnoreHeight(component, font, text, fixedTextWidth, compWidth, textBounds,
+                borderAndIconMargin, 0);
+    }
+
     /**
      * Adapts best {@link Font} size according to {@link Component} height.
      * 
@@ -332,10 +363,12 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
      * @param compHeight The previously calculated maximum allowed text height.
      * @param textBounds The previously calculated text bounds.
      * @param fontSizeToUse The previously calculated best font size (ignoring height).
+     * @param knownMaxHeight The known maximum height allowed for the {@link Component} (already reduced by border and
+     *            icon margin).
      * @return An <code>int</code>: the readapted best font size.
      */
     protected static int computeBestFontSizeAccordingHeight(Font font, FontRenderContext frc, String text,
-            Component component, int compHeight, Rectangle2D textBounds, int fontSizeToUse) {
+            Component component, int compHeight, Rectangle2D textBounds, int fontSizeToUse, int knownMaxHeight) {
         float currentFontHeight;
         if ((text != null) && (!text.isEmpty()) && (frc != null)
                 && ((component instanceof JLabel) || (component instanceof JTextComponent))) {
@@ -348,7 +381,36 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
             currentFontHeight = FontUtils.getFontHeight(font, frc, text, component, textBounds);
         }
         float heightRatio = getBestRatio(compHeight / currentFontHeight);
-        return Math.min(fontSizeToUse, Math.round(font.getSize() * heightRatio));
+        int bestSize = Math.min(fontSizeToUse, Math.round(font.getSize() * heightRatio));
+        // Try to limit to maximum height if it is > 0 (JAVAAPI-644)
+        if (knownMaxHeight > 0) {
+            int newHeight = Math.round(currentFontHeight * (bestSize / font.getSize2D()));
+            if (newHeight > knownMaxHeight) {
+                heightRatio = getBestRatio(knownMaxHeight / (float) newHeight);
+                bestSize *= Math.round(bestSize * heightRatio);
+                if (bestSize == 0) {
+                    bestSize = -1;
+                }
+            }
+        }
+        return bestSize;
+    }
+
+    /**
+     * Adapts best {@link Font} size according to {@link Component} height.
+     * 
+     * @param font The {@link Font}.
+     * @param frc The {@link FontRenderContext}.
+     * @param text The known text.
+     * @param component The {@link Component}.
+     * @param compHeight The previously calculated maximum allowed text height.
+     * @param textBounds The previously calculated text bounds.
+     * @param fontSizeToUse The previously calculated best font size (ignoring height).
+     * @return An <code>int</code>: the readapted best font size.
+     */
+    protected static int computeBestFontSizeAccordingHeight(Font font, FontRenderContext frc, String text,
+            Component component, int compHeight, Rectangle2D textBounds, int fontSizeToUse) {
+        return computeBestFontSizeAccordingHeight(font, frc, text, component, compHeight, textBounds, fontSizeToUse, 0);
     }
 
     /**
@@ -439,12 +501,37 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
             text = button.getText();
             borderAndIconMargin = getBorderAndIconMargin(button);
         }
+        int knownMaxWidth, knownMaxHeight;
+        Dimension maxSize;
+        // Take account of maximum size only if programmatically set (JAVAAPI-644)
+        if ((component == null) || !component.isMaximumSizeSet()) {
+            maxSize = null;
+        } else {
+            maxSize = component.getMaximumSize();
+        }
+        if (maxSize == null) {
+            knownMaxWidth = knownMaxHeight = 0;
+        } else {
+            knownMaxWidth = maxSize.width;
+            knownMaxHeight = maxSize.height;
+            if (knownMaxWidth == Integer.MAX_VALUE) {
+                knownMaxWidth = 0;
+            }
+            if (knownMaxHeight == Integer.MAX_VALUE) {
+                knownMaxHeight = 0;
+            }
+            if (borderAndIconMargin != null) {
+                knownMaxWidth -= borderAndIconMargin.width;
+                knownMaxHeight -= borderAndIconMargin.height;
+            }
+        }
         FontRenderContext frc = getFontRenderContext(component, text);
         if (frc != null) {
             textBounds = font.getStringBounds(text, frc);
         }
         // Step 2 and Step 3: see computeBestFontSizeIgnoreHeight
-        fontSizeToUse = computeBestFontSizeIgnoreHeight(component, font, text, -1, -1, textBounds, borderAndIconMargin);
+        fontSizeToUse = computeBestFontSizeIgnoreHeight(component, font, text, -1, -1, textBounds, borderAndIconMargin,
+                knownMaxWidth);
         if (fontSizeToUse > -1) {
             int compHeight = component.getHeight();
             if (borderAndIconMargin != null) {
@@ -453,7 +540,7 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
 
             // Step 4: Pick a new font size so it will not be larger than the height of label.
             fontSizeToUse = computeBestFontSizeAccordingHeight(font, frc, text, component, compHeight, textBounds,
-                    fontSizeToUse);
+                    fontSizeToUse, knownMaxHeight);
             // Check twice whether font size was misestimated.
             if (frc != null) {
                 int fWidth, fHeight;
@@ -479,35 +566,6 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
                 }
             }
         }
-        if ((component instanceof JComponent) && !(component instanceof IBestFontSizeCalculator)) {
-            JComponent comp = (JComponent) component;
-            Dimension maxSize = comp.getMaximumSize();
-            if ((frc != null) && (maxSize != null)
-                    && (maxSize.width < Integer.MAX_VALUE || maxSize.height < Integer.MAX_VALUE)) {
-                Dimension size;
-                int formerFontSize = 0;
-                while (fontSizeToUse > 1 && fontSizeToUse != formerFontSize) {
-                    formerFontSize = fontSizeToUse;
-                    size = getEstimatedSize(comp, text, font, fontSizeToUse, frc, borderAndIconMargin);
-                    if ((size != null) && (maxSize.width < size.width || maxSize.height < size.height)) {
-                        float ratio = 1;
-                        if (maxSize.width < size.width) {
-                            ratio = ((float) maxSize.width) / (float) size.width;
-                        }
-                        if (maxSize.height < size.height) {
-                            ratio = Math.min(ratio, ((float) maxSize.height) / (float) size.height);
-                        }
-                        fontSizeToUse = Math.round(fontSizeToUse * getBestRatio(ratio));
-                        if (fontSizeToUse < 1) {
-                            fontSizeToUse = 1;
-                        } else if (fontSizeToUse >= formerFontSize) {
-                            fontSizeToUse--;
-                        }
-                    } // end if ((size != null) && (maxSize.width < size.width || maxSize.height < size.height))
-                } // end while (fontSizeToUse > 1 && fontSizeToUse != formerFontSize)
-            } // end if ((frc != null) && (maxSize != null)
-              // && (maxSize.width < Integer.MAX_VALUE || maxSize.height < Integer.MAX_VALUE))
-        } // end if ((component instanceof JComponent) && !(component instanceof IBestFontSizeCalculator))
         return fontSizeToUse;
     }
 
@@ -548,13 +606,14 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
             // and to limit the creation of runnables.
             Runnable runnable = COMPONENT_UPDATERS.get(component);
             if (runnable == null) {
+                // Can't use lambda expression due to the need to access this Runnable
                 runnable = new Runnable() {
                     @Override
                     public void run() {
-                        try {
-                            updateComponentFont(component);
-                        } finally {
                         IN_EDT.remove(this);
+                        // Update component font only if it is showing (optimization discovered during JAVAAPI-644).
+                        if (component.isShowing()) {
+                            updateComponentFont(component);
                         }
                     }
                 };
@@ -655,7 +714,7 @@ public class DynamicFontSizeManager implements IComponentMultiListener, Componen
             component.addPropertyChangeListener(this);
             component.addHierarchyBoundsListener(this);
             component.addHierarchyListener(this);
-            if ((component instanceof JTextComponent)) {
+            if (component instanceof JTextComponent) {
                 JTextComponent textComponent = (JTextComponent) component;
                 rememberTextComponent(textComponent);
                 textComponent.getDocument().addDocumentListener(this);