various minor ui improvements

src/main/java/com/sparrowwallet/sparrow/wallet/PaymentController.java

@@ -110,7 +110,7 @@ public class PaymentController extends WalletFormController implements Initializ
             }
 
             revalidate(amount, amountListener);
-            maxButton.setDisable(!isValidRecipientAddress());
+            maxButton.setDisable(!isValidAddressAndLabel());
             sendController.updateTransaction();
 
             if(validationSupport != null) {
@@ -119,6 +119,7 @@ public class PaymentController extends WalletFormController implements Initializ
         });
 
         label.textProperty().addListener((observable, oldValue, newValue) -> {
+            maxButton.setDisable(!isValidAddressAndLabel());
             sendController.getCreateButton().setDisable(sendController.getWalletTransaction() == null || newValue == null || newValue.isEmpty() || sendController.isInsufficientFeeRate());
             sendController.updateTransaction();
         });
@@ -136,7 +137,7 @@ public class PaymentController extends WalletFormController implements Initializ
             }
         });
 
-        maxButton.setDisable(!isValidRecipientAddress());
+        maxButton.setDisable(!isValidAddressAndLabel());
         sendController.utxoLabelSelectionProperty().addListener((observable, oldValue, newValue) -> {
             maxButton.setText("Max" + newValue);
         });
@@ -175,6 +176,10 @@ public class PaymentController extends WalletFormController implements Initializ
         }
     }
 
+    private boolean isValidAddressAndLabel() {
+        return isValidRecipientAddress() && !label.getText().isEmpty();
+    }
+
     private Address getRecipientAddress() throws InvalidAddressException {
         return Address.fromString(address.getText());
     }

src/main/java/com/sparrowwallet/sparrow/wallet/ReceiveController.java

@@ -125,14 +125,19 @@ public class ReceiveController extends WalletFormController implements Initializ
         if(AppServices.isConnected() && currentOutputs.isEmpty()) {
             lastUsed.setText("Never");
             lastUsed.setGraphic(getUnusedGlyph());
+            address.getStyleClass().remove("error");
         } else if(!currentOutputs.isEmpty()) {
             long count = currentOutputs.size();
             BlockTransactionHashIndex lastUsedReference = currentOutputs.stream().skip(count - 1).findFirst().get();
             lastUsed.setText(lastUsedReference.getHeight() <= 0 ? "Unconfirmed Transaction" : DATE_FORMAT.format(lastUsedReference.getDate()));
             lastUsed.setGraphic(getWarningGlyph());
+            if(!address.getStyleClass().contains("error")) {
+                address.getStyleClass().add("error");
+            }
         } else {
             lastUsed.setText("Unknown");
             lastUsed.setGraphic(null);
+            address.getStyleClass().remove("error");
         }
     }
 

src/main/resources/com/sparrowwallet/sparrow/general.css

@@ -15,6 +15,10 @@
     -fx-pref-height: 25px;
 }
 
+.form .fieldset:horizontal .input-container {
+    -fx-alignment: center-left;
+}
+
 .form .input-container {
     -fx-spacing: 2;
 }

src/main/resources/com/sparrowwallet/sparrow/wallet/payment.fxml

@@ -31,10 +31,18 @@
     <Form GridPane.columnIndex="0" GridPane.rowIndex="0" GridPane.columnSpan="2">
         <Fieldset inputGrow="ALWAYS">
             <Field text="Pay to:">
-                <CopyableTextField fx:id="address" styleClass="address-text-field"/>
+                <CopyableTextField fx:id="address" styleClass="address-text-field">
+                    <tooltip>
+                        <Tooltip text="Address or bitcoin: URI"/>
+                    </tooltip>
+                </CopyableTextField>
             </Field>
             <Field text="Label:">
-                <TextField fx:id="label" />
+                <TextField fx:id="label">
+                    <tooltip>
+                        <Tooltip text="Required to label the transaction (privately in this wallet)"/>
+                    </tooltip>
+                </TextField>
             </Field>
             <Field text="Amount:">
                 <TextField fx:id="amount" styleClass="amount-field" />
@@ -54,7 +62,7 @@
         </Fieldset>
     </Form>
     <Form GridPane.columnIndex="2" GridPane.rowIndex="0">
-        <Fieldset inputGrow="ALWAYS" style="-fx-padding: 2 0 0 0">
+        <Fieldset inputGrow="ALWAYS" style="-fx-padding: 5 0 0 0">
             <HBox>
                 <Button text="" onAction="#scanQrAddress" prefHeight="30">
                     <graphic>