Fixed Emoji image positioning in multiline StyledText

Combination of maximumLineCount and TruncationMode.Elide (or Fade)
breaks Emoji image alignment, pushing the image down. Explicitly
truncating the text fixes the problem, at expense of certain runtime
overhead.

Also, toggle full and truncated Web page preview on tap.

harbour-fernschreiber.pro

@@ -51,6 +51,7 @@ DISTFILES += qml/harbour-fernschreiber.qml \
     qml/components/MessageListViewItem.qml \
     qml/components/MessageListViewItemSimple.qml \
     qml/components/MessageOverlayFlickable.qml \
+    qml/components/MultilineEmojiLabel.qml \
     qml/components/PinnedMessageItem.qml \
     qml/components/PollPreview.qml \
     qml/components/PressEffect.qml \

qml/components/MessageListViewItem.qml

@@ -57,6 +57,8 @@ ListItem {
                 mouseX < (extraContentLoader.x + extraContentLoader.width) &&
                 mouseY < (extraContentLoader.y + extraContentLoader.height)) {
                 extraContent.clicked()
+            } else if (webPagePreviewLoader.item) {
+                webPagePreviewLoader.item.clicked()
             }
         }
     }
@@ -397,17 +399,10 @@ ListItem {
                     active: false
                     asynchronous: true
                     width: parent.width
-                    height: typeof myMessage.content.web_page !== "undefined" ? precalculatedValues.webPagePreviewHeight : 0
+                    height: (status === Loader.Ready) ? item.implicitHeight : myMessage.content.web_page ? precalculatedValues.webPagePreviewHeight : 0
 
                     sourceComponent: Component {
-                        id: webPagePreviewComponent
                         WebPagePreview {
-                            id: webPagePreview
-
-                            onImplicitHeightChanged: {
-                                webPagePreviewLoader.height = webPagePreview.implicitHeight;
-                            }
-
                             webPageData: myMessage.content.web_page
                             width: parent.width
                             highlighted: messageListItem.highlighted

qml/components/MultilineEmojiLabel.qml

@@ -0,0 +1,78 @@
+/*
+    Copyright (C) 2020 Slava Monich and other contributors
+
+    This file is part of Fernschreiber.
+
+    Fernschreiber is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Fernschreiber is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with Fernschreiber. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import QtQuick 2.0
+import Sailfish.Silica 1.0
+import "../js/twemoji.js" as Emoji
+
+// Combination of maximumLineCount and TruncationMode.Elide (or Fade) breaks
+// Emoji image alignment, pushing the image down. This one aligns the image
+// correctly on its line.
+Label {
+    property string rawText
+    property int maxLineCount
+
+    wrapMode: Text.Wrap
+    textFormat: Text.StyledText
+    truncationMode: TruncationMode.Elide
+
+    // lineCount is unreliable for StyledText with images and line breaks
+    readonly property int fontSize: font.pixelSize
+    readonly property int actualLineHeight: (text === rawText) ? fontSize : (fontSize * 6 / 5)
+    readonly property int actualLineCount: Math.floor(implicitHeight/actualLineHeight)
+
+    Component.onCompleted: refitText()
+    onFontSizeChanged: refitText()
+    onWidthChanged: refitText()
+    onRawTextChanged: refitText()
+    onMaxLineCountChanged: refitText()
+
+    function emojify(str) {
+        return Emoji.emojify(str, fontSize)
+    }
+
+    function refitText() {
+        text = emojify(rawText)
+        if (maxLineCount > 0) {
+            var divisor = 1
+            var max = rawText.length
+            var min = max
+            while (actualLineCount > maxLineCount && divisor < rawText.length) {
+                max = min
+                divisor++
+                min = rawText.length/divisor
+                text = emojify(rawText.substr(0, min) + "…")
+            }
+            while (min < max) {
+                var mid = Math.floor((min + max)/2)
+                if (mid === min) {
+                    text = emojify(rawText.substr(0, min) + "…")
+                    break
+                } else {
+                    text = emojify(rawText.substr(0, mid) + "…")
+                    if (actualLineCount > maxLineCount) {
+                        max = mid
+                    } else {
+                        min = mid
+                    }
+                }
+            }
+        }
+    }
+}

qml/components/WebPagePreview.qml

@@ -19,101 +19,86 @@
 import QtQuick 2.6
 import QtGraphicalEffects 1.0
 import Sailfish.Silica 1.0
-import "../components"
-import "../js/twemoji.js" as Emoji
+import WerkWolf.Fernschreiber 1.0
 import "../js/functions.js" as Functions
 
 Column {
-
     id: webPagePreviewColumn
 
     property var webPageData;
-    property var pictureFileInformation;
-    property bool hasImage: false;
     property bool largerFontSize: false;
     property bool highlighted
+    readonly property bool hasImage: picture.fileId !== 0
+    readonly property int fontSize: largerFontSize ? Theme.fontSizeSmall : Theme.fontSizeExtraSmall
 
     spacing: Theme.paddingSmall
 
     Component.onCompleted: {
-        updateWebPage();
-    }
-
-    function updateWebPage() {
         if (webPageData) {
-            if (typeof webPageData.photo !== "undefined") {
-                hasImage = true;
+            if (webPageData.photo) {
                 // Check first which size fits best...
+                var photo
                 for (var i = 0; i < webPageData.photo.sizes.length; i++) {
-                    pictureFileInformation = webPageData.photo.sizes[i].photo;
+                    photo = webPageData.photo.sizes[i].photo;
                     if (webPageData.photo.sizes[i].width >= webPagePreviewColumn.width) {
                         break;
                     }
                 }
-                if (pictureFileInformation.local.is_downloading_completed) {
-                    singleImage.source = pictureFileInformation.local.path;
-                } else {
-                    tdLibWrapper.downloadFile(pictureFileInformation.id);
+                if (photo) {
+                    picture.fileInformation = photo
                 }
             }
         }
     }
 
-    Connections {
-        target: tdLibWrapper
-        onFileUpdated: {
-            if (typeof pictureFileInformation !== "undefined" && fileId === pictureFileInformation.id) {
-                if (fileInformation.local.is_downloading_completed) {
-                    pictureFileInformation = fileInformation;
-                    singleImage.source = fileInformation.local.path;
-                }
-            }
-        }
+    function clicked() {
+        descriptionText.toggleMaxLineCount()
     }
 
-    Label {
+    TDLibFile {
+        id: picture
+        tdlib: tdLibWrapper
+        autoLoad: true
+    }
+
+    MultilineEmojiLabel {
         id: siteNameText
 
         width: parent.width
-        text: webPageData.site_name ? Emoji.emojify(webPageData.site_name, font.pixelSize) : ""
-        font.pixelSize: webPagePreviewColumn.largerFontSize ? Theme.fontSizeSmall : Theme.fontSizeExtraSmall
+        rawText: webPageData.site_name ? webPageData.site_name : ""
+        font.pixelSize: webPagePreviewColumn.fontSize
         font.bold: true
         color: Theme.secondaryHighlightColor
-        truncationMode: TruncationMode.Fade
-        maximumLineCount: 1
-        textFormat: Text.StyledText
-        visible: (text !== "")
+        visible: (rawText !== "")
+        maxLineCount: 1
     }
 
-    Label {
+    MultilineEmojiLabel {
         id: titleText
 
         width: parent.width
-        text: webPageData.title ? Emoji.emojify(webPageData.title, font.pixelSize) : ""
-        font.pixelSize: webPagePreviewColumn.largerFontSize ? Theme.fontSizeSmall : Theme.fontSizeExtraSmall
+        rawText: webPageData.title ? webPageData.title : ""
+        font.pixelSize: webPagePreviewColumn.fontSize
         font.bold: true
-        truncationMode: TruncationMode.Fade
-        wrapMode: Text.Wrap
-        maximumLineCount: 2
-        textFormat: Text.StyledText
-        visible: (text !== "")
+        visible: (rawText !== "")
+        maxLineCount: 2
     }
 
-    Label {
+    MultilineEmojiLabel {
         id: descriptionText
 
         width: parent.width
-        text: webPageData.description ? Emoji.emojify(Functions.enhanceMessageText(webPageData.description), font.pixelSize) : ""
-        font.pixelSize: webPagePreviewColumn.largerFontSize ? Theme.fontSizeSmall : Theme.fontSizeExtraSmall
-        truncationMode: TruncationMode.Fade
-        wrapMode: Text.Wrap
-        maximumLineCount: 3
-        textFormat: Text.StyledText
-        visible: (text !== "")
-        linkColor: Theme.highlightColor
+        rawText: webPageData.description ? Functions.enhanceMessageText(webPageData.description) : ""
+        font.pixelSize: webPagePreviewColumn.fontSize
+        visible: (rawText !== "")
+        readonly property int defaultMaxLineCount: 3
+        maxLineCount: defaultMaxLineCount
         onLinkActivated: {
             Functions.handleLink(link);
         }
+        function toggleMaxLineCount() {
+            maxLineCount = maxLineCount > 0 ? 0 : defaultMaxLineCount
+        }
     }
 
     Item {
@@ -133,15 +118,16 @@ Column {
             fillMode: Image.PreserveAspectCrop
             autoTransform: true
             asynchronous: true
-            visible: hasImage && status === Image.Ready
+            source: picture.isDownloadingCompleted ? picture.path : ""
+            visible: opacity > 0
             opacity: hasImage && status === Image.Ready ? 1 : 0
             layer.enabled: webPagePreviewColumn.highlighted
             layer.effect: PressEffect { source: singleImage }
-            Behavior on opacity { NumberAnimation {} }
+            Behavior on opacity { FadeAnimation {} }
             MouseArea {
                 anchors.fill: parent
                 onClicked: {
-                    pageStack.push(Qt.resolvedUrl("../pages/ImagePage.qml"), { "photoData" : webPageData.photo, "pictureFileInformation" : pictureFileInformation });
+                    pageStack.push(Qt.resolvedUrl("../pages/ImagePage.qml"), { "photoData" : webPageData.photo, "pictureFileInformation" : picture.fileInformation });
                 }
             }
         }
@@ -154,17 +140,12 @@ Column {
     }
 
     Label {
-        id: noPreviewAvailableText
-
         width: parent.width
         text: qsTr("Preview not supported for this link...")
         font.pixelSize: webPagePreviewColumn.largerFontSize ? Theme.fontSizeExtraSmall : Theme.fontSizeTiny
         font.italic: true
         color: Theme.secondaryColor
         truncationMode: TruncationMode.Fade
-        wrapMode: Text.Wrap
-        maximumLineCount: 1
-        textFormat: Text.StyledText
         visible: !siteNameText.visible && !titleText.visible && !descriptionText.visible && !webPagePreviewImageItem.visible
     }