Merge branch 'card-list': the thread pane as a list of cards

Replaces the five-column grid with a single column of three-line cards. Item 53
recorded that the columns, not the cues drawn inside them, were what made the
list read as a table of records; item 20 had already shipped finished, tested
and green and been rejected on sight for exactly that reason.

A card is sender and date, subject with the flag, attachment and reply-count
marks, and tags, at one uniform height. Replies indent under a continuous spine
and show only the tags their thread does not carry. The account colour runs down
the card's left edge, replacing the chip that used to eat a third of every
subject line, with matching swatches in the account dropdown. Sorting newest or
oldest first is new and remembered.

Closes items 20, 51, 53 and 60.

The four defects that mattered were all found by rendering cards to an image and
looking at them, with the suite green through every one: a date clipped on unread
cards because bold is wider than the font the layout measured, an accent bar
painted in a colour identical to the background, an expander pill in a palette
role a theme had made equal to Base, and three separate faults from trusting
notmuch's reply depth to mean structure when it only means how notmuch happened
to thread the mail.

1 files changed, 28 insertions, 113 deletions

diff --git a/src/threadlistview.cpp b/src/threadlistview.cpp
index ef80e09..5a3ce77 100644
--- a/src/threadlistview.cpp
+++ b/src/threadlistview.cpp
@@ -18,123 +18,38 @@
 
 #include "threadlistview.h"
 
-#include "tagchip.h"
+#include "carddelegate.h"
 #include "threadlistmodel.h"
 
-#include <QPaintEvent>
-#include <QPainter>
-#include <QScrollBar>
+#include <QMouseEvent>
 
-void ThreadListView::paintEvent(QPaintEvent *event)
+void ThreadListView::mousePressEvent(QMouseEvent *event)
 {
-    QTableView::paintEvent(event);
-
-    if (!model())
-        return;
-
-    QPainter painter(viewport());
-
-    // Two fonts, deliberately. The row's own font fixes where the text band
-    // ends, and the pills are drawn a size smaller: at the same size they read
-    // as a second row of content competing with the subject, rather than as
-    // annotation beneath it.
-    const QFontMetrics rowMetrics(font());
-    const QFont pillFont = SubjectDelegate::pillFont(font());
-    const QFontMetrics metrics(pillFont);
-    painter.setFont(pillFont);
-
-    // Only the rows actually on screen. Walking the whole model would paint
-    // thousands of strips outside the viewport on a large query.
-    const int first = rowAt(0);
-    const int last = rowAt(viewport()->height() - 1);
-    const int lastRow = last >= 0 ? last : model()->rowCount() - 1;
-
-    for (int row = qMax(0, first); row <= lastRow; ++row) {
-        const QModelIndex index =
-            model()->index(row, ThreadListModel::SubjectColumn);
-
-        const int rowTop = rowViewportPosition(row);
-        const int height = rowHeight(row);
-        if (height <= 0)
-            continue;
-
-        // The strip's band, filled to match the row before anything is drawn
-        // on it.
-        //
-        // A QTableView paints alternating colours and the selection PER CELL,
-        // so nothing paints the width to the right of the last column, and
-        // nothing paints the band at all where a column does not reach. Left
-        // unfilled, an alternate-coloured or selected row shows the viewport
-        // background in a strip across its lower half. Filled for every
-        // visible row, not only tagged ones, since an untagged row has the
-        // same band to account for.
-        // Starting at the date column, NOT at the viewport edge. The two
-        // leading columns hold the attachment and flag glyphs, centred in the
-        // full row height, so a band drawn over them cuts those glyphs in half.
-        const int bandLeft =
-            columnViewportPosition(ThreadListModel::DateColumn);
-        const QRect band(bandLeft, rowTop + SubjectDelegate::kRowPadding
-                                       + rowMetrics.height(),
-                         viewport()->width() - bandLeft,
-                         height - SubjectDelegate::kRowPadding
-                                - rowMetrics.height());
-
-        // The model's own row colour wins where it has one: a deleted or spam
-        // thread fills its cells with crimson or orange, and painting the base
-        // colour across the band beneath them would cut the row in half.
-        const QVariant background = index.data(Qt::BackgroundRole);
-
-        if (background.isValid())
-            painter.fillRect(band, background.value<QBrush>());
-        else if (selectionModel() && selectionModel()->isRowSelected(row))
-            painter.fillRect(band, palette().brush(QPalette::Highlight));
-        else if (alternatingRowColors() && (row % 2))
-            painter.fillRect(band, palette().brush(QPalette::AlternateBase));
-        else
-            painter.fillRect(band, palette().brush(QPalette::Base));
-
-        const QStringList tags =
-            index.data(ThreadListModel::PillTagsRole).toStringList();
-        if (tags.isEmpty())
-            continue;
-
-        const QVariantList colours =
-            index.data(ThreadListModel::PillColoursRole).toList();
-
-        // The band the cells leave free, below the text they draw in the
-        // upper one. Measured from SubjectDelegate by both sides, so neither
-        // can drift into the other's half. The row's own font metrics set the
-        // text band; the strip's smaller font must not be used for it, or the
-        // pills ride up over the date and sender.
-        const int top = rowTop + SubjectDelegate::kRowPadding
-                      + rowMetrics.height() + TagChip::kSpacing;
-
-        // Aligned with the first text column rather than the viewport edge:
-        // the two leading columns are narrow markers for the attachment and
-        // flag glyphs, and a strip starting at x=0 paints straight over them.
-        // Indented past the date column's own left edge rather than flush with
-        // it: a chip starting exactly where the column does reads as part of
-        // the column rather than as a strip laid under the row.
-        int x = columnViewportPosition(ThreadListModel::DateColumn)
-              + TagChip::kSpacing * 2;
-        const int available = viewport()->width() - TagChip::kSpacing;
-
-        for (int i = 0; i < tags.size(); ++i) {
-            const QSize size = TagChip::sizeFor(metrics, tags.at(i));
-
-            // Stop rather than wrap or elide. A row that grew to fit its tags
-            // would break the uniform height the list depends on, and half a
-            // chip reads as a rendering fault.
-            if (x + size.width() > available)
-                break;
-
-            const QColor colour = i < colours.size()
-                ? colours.at(i).value<QColor>()
-                : QColor(0x55, 0x55, 0x5f);
-
-            TagChip::paint(&painter, QRect(x, top, size.width(), size.height()),
-                           tags.at(i), colour);
-            x += size.width() + TagChip::kSpacing;
+    const QModelIndex index = indexAt(event->pos());
+
+    // The reply count IS the expander. Anything outside its rect selects the
+    // card and opens it, which is what the rest of the card is for.
+    if (event->button() == Qt::LeftButton && index.isValid()
+        && index.data(ThreadListModel::ReplyCountRole).toInt() > 0) {
+
+        QStyleOptionViewItem option;
+        initViewItemOption(&option);
+        option.rect = visualRect(index);
+        // State_Open decides which way the glyph points, and the rect is the
+        // same either way, but pass it so the layout sees the true state.
+        if (isExpanded(index))
+            option.state |= QStyle::State_Open;
+
+        if (CardDelegate::expanderRectFor(option, index)
+                .contains(event->pos())) {
+            setExpanded(index, !isExpanded(index));
+            // Swallowed, so expanding does not also load the thread into the
+            // message pane: it is a request to see the thread's shape, not to
+            // read it.
+            event->accept();
+            return;
         }
     }
+
+    QTreeView::mousePressEvent(event);
 }