feat: add Go to message action in various places (#3953)

* feat: add `Go to message` action in search popup

* chore: add changelog entry

* fix: only scroll if the scrollbar is shown

* fix: go to message when view isn't focused

* feat: animate highlighted message

* fix: missing includes

* fix: order of initialization

* fix: add `ChannelView::mayContainMessage` to filter messages

* feat: add `Go to message` action in `/mentions`

* fix: ignore any mentions channel when searching for split

* feat: add `Go to message` action in reply-threads

* fix: remove redundant `source` parameter

* feat: add `Go to message` action in user-cards

* feat: add link to deleted message

* fix: set current time to 0 when starting animation

* chore: update changelog

* fix: add default case (unreachable)

* chore: removed unused variable

* fix: search in mentions

* fix: always attempt to focus split

* fix: rename `Link::MessageId` to `Link::JumpToMessage`

* fix: rename `selectAndScrollToMessage` to `scrollToMessage`

* fix: rename internal `scrollToMessage` to `scrollToMessageLayout`

* fix: deleted message link in search popup

* chore: reword explanation

* fix: use for-loop instead of `std::find_if`

* refactor: define highlight colors in `BaseTheme`

* core: replace `iff` with `if`

* fix: only return if the message found

* Reword/phrase/dot changelog entries

Co-authored-by: pajlada <rasmus.karlsson@pajlada.com>

src/widgets/helper/ChannelView.hpp

@@ -3,6 +3,7 @@
 #include <QPaintEvent>
 #include <QScroller>
 #include <QTimer>
+#include <QVariantAnimation>
 #include <QWheelEvent>
 #include <QWidget>
 #include <pajlada/signals/signal.hpp>
@@ -83,6 +84,17 @@ public:
     const boost::optional<MessageElementFlags> &getOverrideFlags() const;
     void updateLastReadMessage();
 
+    /**
+     * Attempts to scroll to a message in this channel.
+     * @return <code>true</code> if the message was found and highlighted.
+     */
+    bool scrollToMessage(const MessagePtr &message);
+    /**
+     * Attempts to scroll to a message id in this channel.
+     * @return <code>true</code> if the message was found and highlighted.
+     */
+    bool scrollToMessageId(const QString &id);
+
     /// Pausing
     bool pausable() const;
     void setPausable(bool value);
@@ -119,6 +131,13 @@ public:
     void showUserInfoPopup(const QString &userName,
                            QString alternativePopoutChannel = QString());
 
+    /**
+     * @brief This method is meant to be used when filtering out channels.
+     *        It <b>must</b> return true if a message belongs in this channel.
+     *        It <b>might</b> return true if a message doesn't belong in this channel.
+     */
+    bool mayContainMessage(const MessagePtr &message);
+
     pajlada::Signals::Signal<QMouseEvent *> mouseDown;
     pajlada::Signals::NoArgSignal selectionChanged;
     pajlada::Signals::Signal<HighlightState> tabHighlightRequested;
@@ -208,6 +227,14 @@ private:
     void enableScrolling(const QPointF &scrollStart);
     void disableScrolling();
 
+    /**
+     * Scrolls to a message layout that must be from this view.
+     *
+     * @param layout Must be from this channel.
+     * @param messageIdx Must be an index into this channel.
+     */
+    void scrollToMessageLayout(MessageLayout *layout, size_t messageIdx);
+
     void setInputReply(const MessagePtr &message);
     void showReplyThreadPopup(const MessagePtr &message);
     bool canReplyToMessages() const;
@@ -241,6 +268,7 @@ private:
 
     Scrollbar *scrollBar_;
     EffectLabel *goToBottom_;
+    bool showScrollBar_ = false;
 
     FilterSetPtr channelFilters_;
 
@@ -272,6 +300,11 @@ private:
     QPointF currentMousePosition_;
     QTimer scrollTimer_;
 
+    // We're only interested in the pointer, not the contents
+    MessageLayout *highlightedMessage_;
+    QVariantAnimation highlightAnimation_;
+    void setupHighlightAnimationColors();
+
     struct {
         QCursor neutral;
         QCursor up;