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neminathaneminatha
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Have chats respond to PgUp and PgDown
Resolves #2087
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‎apps/desktop/desktop/src/main/java/bisq/desktop/common/utils/PageScrollHandler.java‎

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/*
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* This file is part of Bisq.
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*
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* Bisq is free software: you can redistribute it and/or modify it
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* under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or (at
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* your option) any later version.
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*
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* Bisq is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
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* License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with Bisq. If not, see <http://www.gnu.org/licenses/>.
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*/
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package bisq.desktop.common.utils;
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import bisq.desktop.components.list_view.ListViewUtil;
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import javafx.event.EventHandler;
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import javafx.geometry.Orientation;
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import javafx.scene.Node;
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import javafx.scene.Scene;
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import javafx.scene.control.ListView;
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import javafx.scene.control.ScrollBar;
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import javafx.scene.control.TextInputControl;
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import javafx.scene.input.KeyCode;
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import javafx.scene.input.KeyEvent;
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import lombok.extern.slf4j.Slf4j;
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import org.fxmisc.easybind.Subscription;
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import java.util.Objects;
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/**
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* Handler to enable page-wise keyboard scrolling for a JavaFX ListView Control.
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* <p>
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* Utility that installs a key event handler on a JavaFX ListView to perform page-wise
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* scrolling when the PAGE_UP and PAGE_DOWN keys are pressed. The handler locates the
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* control's vertical ScrollBar (if present) and adjusts its value by the ScrollBar's
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* block increment, mimicking a page click on the scrollbar trough. The key event is
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* consumed only when a scroll action is performed.
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* </p>
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* <p>
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* Note: the handler is registered using {@code addEventFilter}, i.e. it runs in the
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* capturing phase (filter phase) while events travel from the root toward the target node.
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* This allows centralized preprocessing of PageUp/PageDown keys for the ListView before
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* the event reaches the target node.
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* </p>
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* <p>
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* To ensure that input fields keep their normal keyboard behavior, the handler
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* checks with {@link #isInlineEditorActive()} whether a descendant editable
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* {@link TextInputControl} is currently focused. If an editor is active, the filter does
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* not consume the event — the event will continue to the normal target/bubbling phase and
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* can be handled by the editor. If no editor is focused, the filter consumes the event
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* (via {@code event.consume()}) after a scroll occurred.
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* </p>
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* <p>
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* Typical usage:
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* <ul>
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* <li>Instantiate with a JavaFX ListView Control.</li>
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* <li>Call {@link #subscribe()} to enable the handler.</li>
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* <li>Call {@link #unsubscribe()} to remove the handler.</li>
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* </ul>
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* </p>
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* <p>
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* Note: methods that inspect or modify the scene graph (e.g. locating ScrollBars)
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* must be called on the JavaFX Application Thread.
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* </p>
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*/
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@Slf4j
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public class PageScrollHandler implements Subscription {
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private final ListView<?> listView;
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private final EventHandler<KeyEvent> keyEventFilter;
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public PageScrollHandler(ListView<?> listView) {
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this.listView = Objects.requireNonNull(listView);
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this.keyEventFilter = createKeyEventFilter();
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}
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private EventHandler<KeyEvent> createKeyEventFilter() {
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return event -> {
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if (event.getCode() == KeyCode.PAGE_UP) {
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if (!isInlineEditorActive()) {
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if (scrollPageUp()) {
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event.consume();
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}
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}
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} else if (event.getCode() == KeyCode.PAGE_DOWN) {
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if (!isInlineEditorActive()) {
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if (scrollPageDown()) {
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event.consume();
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}
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}
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}
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};
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}
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public void subscribe() {
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unsubscribe();
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listView.addEventFilter(KeyEvent.KEY_PRESSED, keyEventFilter);
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}
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public void unsubscribe() {
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listView.removeEventFilter(KeyEvent.KEY_PRESSED, keyEventFilter);
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}
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public boolean scrollPageUp() {
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return ListViewUtil.findScrollbar(listView, Orientation.VERTICAL)
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.map(this::adjustScrollBarBlockDecrement)
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.orElse(false);
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}
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public boolean scrollPageDown() {
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return ListViewUtil.findScrollbar(listView, Orientation.VERTICAL)
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.map(this::adjustScrollBarBlockIncrement)
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.orElse(false);
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}
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private boolean adjustScrollBarBlockDecrement(ScrollBar vbar) {
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return adjustScrollBar(vbar, -vbar.getBlockIncrement());
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}
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private boolean adjustScrollBarBlockIncrement(ScrollBar vbar) {
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return adjustScrollBar(vbar, vbar.getBlockIncrement());
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}
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private boolean adjustScrollBar(ScrollBar vbar, double increment) {
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double oldValue = vbar.getValue();
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vbar.adjustValue(oldValue + increment);
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return oldValue != vbar.getValue();
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}
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private boolean isInlineEditorActive() {
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Scene scene = listView.getScene();
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if (scene == null) return false;
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Node focusOwner = scene.getFocusOwner();
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return isEditable(focusOwner) && isChildOfList(focusOwner);
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}
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private boolean isEditable(Node focusOwner) {
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return focusOwner instanceof TextInputControl && ((TextInputControl) focusOwner).isEditable();
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}
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private boolean isChildOfList(Node node) {
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while (node != null) {
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if (node == listView) return true;
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node = node.getParent();
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}
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return false;
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}
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}

‎apps/desktop/desktop/src/main/java/bisq/desktop/main/content/chat/message_container/ChatMessageContainerController.java‎

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@@ -217,6 +217,14 @@ void onArrowUpKeyPressed() {
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chatMessagesListController.editMyLastMessage();
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}
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boolean onPageUpKeyPressed() {
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return chatMessagesListController.scrollPageUp();
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}
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boolean onPageDownKeyPressed() {
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return chatMessagesListController.scrollPageDown();
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}
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void onUserProfileSelected(UserProfile user) {
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String content = model.getTextInput().get().replaceAll("@[a-zA-Z\\d]*$", "@" + user.getUserName() + " ");
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model.getTextInput().set(content);

‎apps/desktop/desktop/src/main/java/bisq/desktop/main/content/chat/message_container/ChatMessageContainerView.java‎

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import javafx.scene.image.ImageView;
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import javafx.scene.input.KeyCode;
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import javafx.scene.input.KeyEvent;
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import javafx.scene.input.MouseEvent;
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import javafx.scene.layout.HBox;
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import javafx.scene.layout.Pane;
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import javafx.scene.layout.Priority;
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@Override
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protected void onViewAttached() {
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// Consume mouse pressed events on the root to prevent them from propagating to underlying layers
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root.setOnMousePressed(MouseEvent::consume);
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userProfileSelectionRoot.visibleProperty().bind(model.getShouldShowUserProfileSelection());
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userProfileSelectionRoot.managedProperty().bind(model.getShouldShowUserProfileSelection());
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myProfileCatHashImageView.visibleProperty().bind(model.getShouldShowUserProfile());
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inputField.removeEventFilter(KEY_PRESSED, keyPressedHandler);
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sendButton.setOnAction(null);
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userMentionPopup.cleanup();
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root.setOnMousePressed(null);
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}
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private VBox createAndGetBottomBar(UserProfileSelection userProfileSelection) {
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inputField.positionCaret(0);
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}
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}
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} else if (keyEvent.getCode() == KeyCode.PAGE_UP) {
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if (inputField.getText().isEmpty()) {
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if (controller.onPageUpKeyPressed()) {
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keyEvent.consume();
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}
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}
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} else if (keyEvent.getCode() == KeyCode.PAGE_DOWN) {
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if (inputField.getText().isEmpty()) {
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if (controller.onPageDownKeyPressed()) {
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keyEvent.consume();
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}
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}
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}
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}
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}

‎apps/desktop/desktop/src/main/java/bisq/desktop/main/content/chat/message_container/list/ChatMessagesListController.java‎

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applyScrollValue(1);
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}
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public boolean scrollPageUp() {
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return view.getPageScrollHandler().scrollPageUp();
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}
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public boolean scrollPageDown() {
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return view.getPageScrollHandler().scrollPageDown();
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}
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/* --------------------------------------------------------------------- */
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// Private

‎apps/desktop/desktop/src/main/java/bisq/desktop/main/content/chat/message_container/list/ChatMessagesListView.java‎

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import bisq.chat.ChatChannel;
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import bisq.chat.ChatMessage;
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import bisq.desktop.common.ManagedDuration;
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import bisq.desktop.common.utils.PageScrollHandler;
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import bisq.desktop.components.controls.Badge;
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import bisq.desktop.components.controls.BisqTooltip;
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import bisq.desktop.components.list_view.ListViewUtil;
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import javafx.scene.layout.Priority;
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import javafx.scene.layout.StackPane;
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import javafx.scene.layout.VBox;
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import lombok.AccessLevel;
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import lombok.Getter;
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import lombok.extern.slf4j.Slf4j;
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import org.fxmisc.easybind.EasyBind;
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private final Label placeholderTitle = new Label("");
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private final Label placeholderDescription = new Label("");
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private final Pane scrollDownBackground;
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@Getter(AccessLevel.PACKAGE)
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private final PageScrollHandler pageScrollHandler;
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private Optional<ScrollBar> scrollBar = Optional.empty();
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private Subscription hasUnreadMessagesPin, showScrolledDownButtonPin;
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private Timeline fadeInScrollDownBadgeTimeline;
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listView.setSelectionModel(new NoSelectionModel<>());
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VBox.setVgrow(listView, Priority.ALWAYS);
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pageScrollHandler = new PageScrollHandler(listView);
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scrollDownBackground = new Pane();
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scrollDownBackground.getStyleClass().add("scroll-down-bg");
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model.getLayoutChildrenDone().bind(root.getLayoutChildrenDone());
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scrollDownBadge.setOnMouseClicked(e -> controller.onScrollToBottom());
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pageScrollHandler.subscribe();
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}
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@Override
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model.getLayoutChildrenDone().unbind();
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hasUnreadMessagesPin.unsubscribe();
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showScrolledDownButtonPin.unsubscribe();
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pageScrollHandler.unsubscribe();
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Tooltip.uninstall(scrollDownBadge, scrollDownTooltip);
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