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made the first prototype, scrolling and word wrapping seems to be working

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This commit is contained in:
Blue 2020-08-17 13:27:14 +03:00
parent e54cff0f0c
commit e1eea2f3a2
2 changed files with 132 additions and 18 deletions
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145
ui/utils/feedview.cpp
View File

@ -20,13 +20,19 @@
#include <QPaintEvent>
#include <QPainter>
#include <QScrollBar>
#include <QDebug>
constexpr int maxMessageHeight = 10000;
constexpr int approximateSingleMessageHeight = 20;
FeedView::FeedView(QWidget* parent):
QAbstractItemView(parent),
hints()
hints(),
vo(0)
{
horizontalScrollBar()->setRange(0, 0);
verticalScrollBar()->setSingleStep(approximateSingleMessageHeight);
}
FeedView::~FeedView()
@ -35,6 +41,17 @@ FeedView::~FeedView()
QModelIndex FeedView::indexAt(const QPoint& point) const
{
int32_t totalHeight = viewport()->height() + vo;
if (point.y() <= totalHeight) { //if it's bigger - someone wants to know the index below the feed beginning, it's invalid
uint32_t y = totalHeight - point.y();
for (std::deque<Hint>::size_type i = 0; i < hints.size(); ++i) {
if (y > hints[i].offset) {
return model()->index(i - 1, 0, rootIndex());
}
}
}
return QModelIndex();
}
@ -45,11 +62,12 @@ void FeedView::scrollTo(const QModelIndex& index, QAbstractItemView::ScrollHint
QRect FeedView::visualRect(const QModelIndex& index) const
{
if (!index.isValid() || index.row() >= hints.size()) {
qDebug() << "visualRect for" << index.row();
return QRect();
} else {
const Hint& hint = hints.at(index.row());
const QWidget* vp = viewport();
return QRect(0, vp->height() - hint.height - hint.offset, vp->width(), hint.height);
return QRect(0, vp->height() - hint.height - hint.offset + vo, vp->width(), hint.height);
}
}
@ -60,7 +78,7 @@ int FeedView::horizontalOffset() const
bool FeedView::isIndexHidden(const QModelIndex& index) const
{
return true;
return false;
}
QModelIndex FeedView::moveCursor(QAbstractItemView::CursorAction cursorAction, Qt::KeyboardModifiers modifiers)
@ -74,7 +92,7 @@ void FeedView::setSelection(const QRect& rect, QItemSelectionModel::SelectionFla
int FeedView::verticalOffset() const
{
return 0;
return vo;
}
QRegion FeedView::visualRegionForSelection(const QItemSelection& selection) const
@ -84,22 +102,80 @@ QRegion FeedView::visualRegionForSelection(const QItemSelection& selection) cons
void FeedView::rowsInserted(const QModelIndex& parent, int start, int end)
{
scheduleDelayedItemsLayout();
updateGeometries();
QAbstractItemView::rowsInserted(parent, start, end);
}
void FeedView::updateGeometries()
{
qDebug() << "updateGeometries";
QAbstractItemView::updateGeometries();
const QAbstractItemModel* m = model();
QStyleOptionViewItem option = viewOptions();
uint32_t previousOffset = 0;
QScrollBar* bar = verticalScrollBar();
hints.clear();
QAbstractItemView::updateGeometries();
const QStyle* st = style();
const QAbstractItemModel* m = model();
QRect layoutBounds = QRect(QPoint(), maximumViewportSize());
QStyleOptionViewItem option = viewOptions();
option.rect.setHeight(maxMessageHeight);
option.rect.setWidth(layoutBounds.width());
int frameAroundContents = 0;
int verticalScrollBarExtent = st->pixelMetric(QStyle::PM_ScrollBarExtent, 0, bar);
bool layedOut = false;
if (verticalScrollBarExtent != 0 && verticalScrollBarPolicy() == Qt::ScrollBarAsNeeded && m->rowCount() * approximateSingleMessageHeight < layoutBounds.height()) {
hints.clear();
layedOut = tryToCalculateGeometriesWithNoScrollbars(option, m, layoutBounds.height());
}
if (layedOut) {
bar->setRange(0, 0);
} else {
int verticalMargin = 0;
if (st->styleHint(QStyle::SH_ScrollView_FrameOnlyAroundContents)) {
frameAroundContents = st->pixelMetric(QStyle::PM_DefaultFrameWidth) * 2;
}
if (verticalScrollBarPolicy() == Qt::ScrollBarAsNeeded) {
verticalMargin = verticalScrollBarExtent + frameAroundContents;
}
layoutBounds.adjust(0, 0, -verticalMargin, 0);
option.features |= QStyleOptionViewItem::WrapText;
option.rect.setWidth(layoutBounds.width());
hints.clear();
uint32_t previousOffset = 0;
for (int i = 0, size = m->rowCount(); i < size; ++i) {
QModelIndex index = m->index(i, 0, rootIndex());
int height = itemDelegate(index)->sizeHint(option, index).height();
hints.emplace_back(Hint({
false,
previousOffset,
static_cast<uint32_t>(height)
}));
previousOffset += height;
}
bar->setRange(0, previousOffset - layoutBounds.height());
bar->setPageStep(layoutBounds.height());
bar->setValue(previousOffset - layoutBounds.height() - vo);
}
}
bool FeedView::tryToCalculateGeometriesWithNoScrollbars(const QStyleOptionViewItem& option, const QAbstractItemModel* m, uint32_t totalHeight)
{
uint32_t previousOffset = 0;
bool success = true;
for (int i = 0, size = m->rowCount(); i < size; ++i) {
QModelIndex index = m->index(i, 0, QModelIndex());
QModelIndex index = m->index(i, 0, rootIndex());
int height = itemDelegate(index)->sizeHint(option, index).height();
if (previousOffset + height > totalHeight) {
success = false;
break;
}
hints.emplace_back(Hint({
false,
previousOffset,
@ -107,19 +183,52 @@ void FeedView::updateGeometries()
}));
previousOffset += height;
}
return success;
}
void FeedView::paintEvent(QPaintEvent* event)
{
qDebug() << "paint";
qDebug() << "paint" << event->rect();
const QAbstractItemModel* m = model();
QRect zone = event->rect().translated(horizontalOffset(), -verticalOffset());
QPainter painter(viewport());
QStyleOptionViewItem option = viewOptions();
QWidget* vp = viewport();
QRect zone = event->rect().translated(0, -vo);
uint32_t vph = vp->height();
int32_t y1 = zone.y();
int32_t y2 = y1 + zone.height();
for (int i = 0, size = m->rowCount(); i < size; ++i) {
QModelIndex index = m->index(i, 0, QModelIndex());
bool inZone = false;
std::deque<QModelIndex> toRener;
for (std::deque<Hint>::size_type i = 0; i < hints.size(); ++i) {
const Hint& hint = hints[i];
int32_t relativeY1 = vph - hint.offset - hint.height;
if (!inZone) {
if (y2 > relativeY1) {
inZone = true;
}
}
if (inZone) {
toRener.emplace_back(m->index(i, 0, rootIndex()));
}
if (y1 > relativeY1) {
break;
}
}
QPainter painter(vp);
QStyleOptionViewItem option = viewOptions();
option.features = QStyleOptionViewItem::WrapText;
for (const QModelIndex& index : toRener) {
option.rect = visualRect(index);
itemDelegate(index)->paint(&painter, option, index);
}
}
void FeedView::verticalScrollbarValueChanged(int value)
{
vo = verticalScrollBar()->maximum() - value;
QAbstractItemView::verticalScrollbarValueChanged(vo);
}

5
ui/utils/feedview.h
View File

@ -45,6 +45,7 @@ public:
protected slots:
void rowsInserted(const QModelIndex & parent, int start, int end) override;
void verticalScrollbarValueChanged(int value) override;
protected:
int verticalOffset() const override;
@ -52,6 +53,9 @@ protected:
void paintEvent(QPaintEvent * event) override;
void updateGeometries() override;
private:
bool tryToCalculateGeometriesWithNoScrollbars(const QStyleOptionViewItem& option, const QAbstractItemModel* model, uint32_t totalHeight);
private:
struct Hint {
bool dirty;
@ -59,6 +63,7 @@ private:
uint32_t height;
};
std::deque<Hint> hints;
int vo;
};