#339 fixed, hopefully

digit changes should no longer be destructive
vaadin-miki · Jan 11, 2022 · 4eeea5c · 4eeea5c
1 parent b736a24
commit 4eeea5c
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Showing 3 changed files with 50 additions and 8 deletions.
diff --git a/superfields/src/main/java/org/vaadin/miki/superfields/numbers/AbstractSuperNumberField.java b/superfields/src/main/java/org/vaadin/miki/superfields/numbers/AbstractSuperNumberField.java
@@ -4,6 +4,7 @@
 import com.vaadin.flow.component.BlurNotifier;
 import com.vaadin.flow.component.Component;
 import com.vaadin.flow.component.FocusNotifier;
+import com.vaadin.flow.component.HasValue;
 import com.vaadin.flow.component.customfield.CustomField;
 import com.vaadin.flow.component.dependency.CssImport;
 import com.vaadin.flow.component.textfield.HasPrefixAndSuffix;
@@ -39,6 +40,7 @@
 import java.text.ParseException;
 import java.util.Locale;
 import java.util.Optional;
+import java.util.function.Consumer;
 
 /**
  * Base class for super number fields.
@@ -128,6 +130,8 @@ public abstract class AbstractSuperNumberField<T extends Number, SELF extends Ab
 
     private boolean focused = false;
 
+    private Registration innerFieldValueChangeRegistration;
+
     /**
      * Creates the field.
      * @param defaultValue Default value to use on startup and when there are errors.
@@ -163,9 +167,32 @@ protected AbstractSuperNumberField(T defaultValue, SerializablePredicate<T> nega
         this.field.addBlurListener(this::onFieldBlurred);
         this.field.addTextSelectionListener(this::onTextSelected);
         // the following line allows for ValueChangeMode to be effective (#337)
-        // at the same time, it makes setting fraction/integer digits destructive
+        // at the same time, it makes setting fraction/integer digits destructive (see #339)
         // (because without it the value would be updated on blur, and not on every change)
-        this.field.addValueChangeListener(event -> this.updateValue());
+        this.listenToValueChangesFromInnerField();
+    }
+
+    private void listenToValueChangesFromInnerField() {
+        if(this.innerFieldValueChangeRegistration == null)
+            this.innerFieldValueChangeRegistration = this.field.addValueChangeListener(this::onFieldChanged);
+    }
+
+    /**
+     * Runs the given consumer and ignores any value change effects that happen during that time.
+     * @param consumer An action to perform. Will receive {@code this} as a parameter.
+     */
+    private void ignoreValueChangesFromInnerField(Consumer<AbstractSuperNumberField<T, SELF>> consumer) {
+        final boolean restore = this.innerFieldValueChangeRegistration != null;
+        if(restore)
+            this.innerFieldValueChangeRegistration.remove();
+        this.innerFieldValueChangeRegistration = null;
+        consumer.accept(this);
+        if(restore)
+            this.listenToValueChangesFromInnerField();
+    }
+
+    private void onFieldChanged(HasValue.ValueChangeEvent<String> event) {
+        this.updateValue();
     }
 
     /**
@@ -247,7 +274,7 @@ protected void setIntegerPartOptional(boolean optional) {
      */
     protected void setMinimumFractionDigits(int digits) {
         this.format.setMinimumFractionDigits(digits);
-        this.updateRegularExpression();
+        this.updateRegularExpression(true);
     }
 
     /**
@@ -258,7 +285,7 @@ protected void setMinimumFractionDigits(int digits) {
      */
     protected void setMaximumFractionDigits(int digits) {
         this.format.setMaximumFractionDigits(digits);
-        this.updateRegularExpression();
+        this.updateRegularExpression(true);
     }
 
     /**
@@ -269,7 +296,7 @@ protected void setMaximumFractionDigits(int digits) {
      */
     public void setMaximumIntegerDigits(int digits) {
         this.format.setMaximumIntegerDigits(digits);
-        this.updateRegularExpression();
+        this.updateRegularExpression(true);
     }
 
     /**
@@ -284,6 +311,18 @@ public final SELF withMaximumIntegerDigits(int digits) {
         return (SELF)this;
     }
 
+    /**
+     * Builds the regular expression and optionally ignores value change events from the underlying field.
+     * Basically allows the representation of the value to be changed, but not the value itself.
+     * @param ignoreValueChangeFromField Whether to ignore value change events coming from the underlying field.
+     */
+    protected final void updateRegularExpression(boolean ignoreValueChangeFromField) {
+        // hopefully fixes #339
+        if(ignoreValueChangeFromField)
+            this.ignoreValueChangesFromInnerField(AbstractSuperNumberField::updateRegularExpression);
+        else this.updateRegularExpression();
+    }
+
     /**
      * Builds the regular expression for matching the input.
      */

diff --git a/superfields/src/test/java/org/vaadin/miki/superfields/numbers/SuperBigDecimalFieldTest.java b/superfields/src/test/java/org/vaadin/miki/superfields/numbers/SuperBigDecimalFieldTest.java
@@ -33,15 +33,18 @@ public void testMinimumFractionDigits() {
         this.getField().setValue(TEN_DIGITS_PLUS_TWO);
         this.getField().setMinimumFractionDigits(6);
         Assert.assertEquals(FORMATTED_TEN_DIGITS_PLUS_TWO+"0000", this.getField().getRawValue());
-        Assert.assertEquals(new BigDecimal("1234567890.120000"), this.getField().getValue());
+        Assert.assertEquals(TEN_DIGITS_PLUS_TWO, this.getField().getValue());
     }
 
     @Test
     public void testMaximumFractionDigits() {
         this.getField().setValue(TEN_DIGITS_PLUS_TWO);
         this.getField().setMaximumFractionDigits(1);
         Assert.assertEquals("1 234 567 890,1", this.getField().getRawValue());
-        Assert.assertEquals(new BigDecimal("1234567890.1"), this.getField().getValue());
+        Assert.assertEquals(TEN_DIGITS_PLUS_TWO, this.getField().getValue());
+        this.getField().setMaximumFractionDigits(2);
+        Assert.assertEquals(FORMATTED_TEN_DIGITS_PLUS_TWO, this.getField().getRawValue());
+        Assert.assertEquals(TEN_DIGITS_PLUS_TWO, this.getField().getValue());
     }
 
     @Override

diff --git a/superfields/src/test/java/org/vaadin/miki/superfields/numbers/SuperDoubleFieldTest.java b/superfields/src/test/java/org/vaadin/miki/superfields/numbers/SuperDoubleFieldTest.java
@@ -33,7 +33,7 @@ public void testMaximumFractionDigits() {
         this.getField().setValue(1.234d);
         this.getField().setMaximumFractionDigits(1);
         Assert.assertEquals("1,2", this.getField().getRawValue());
-        Assert.assertEquals(1.2, this.getField().getValue(), 0);
+        Assert.assertEquals(1.234d, this.getField().getValue(), 0);
     }
 
 }