PDF multipage viewer: iterate search results

This version still has separate PdfSearchModel instances on each page,
but now there are buttons to iterate and highlight the search results
in order.  When you come to the last result on one page, hitting the
"Find Next" button will jump to the next page, and keep jumping forward
from there until another result is found.  Unfortunately this jumping
takes time if it skips over a lot of pages because of empty search
results.  That seems to be another reason to make PdfSearchModel into a
whole-document search model and use one instance.

Also reorganize PdfMultiPageView.qml's public API into sections
according to functionality rather than by type.

Change-Id: I677a764fcbf231b2656aff8abe7240a27582a696
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

1 files changed, 68 insertions, 32 deletions

diff --git a/src/pdf/quick/qml/PdfMultiPageView.qml b/src/pdf/quick/qml/PdfMultiPageView.qml
index acef9fbea..bc5134267 100644
--- a/src/pdf/quick/qml/PdfMultiPageView.qml
+++ b/src/pdf/quick/qml/PdfMultiPageView.qml
@@ -58,32 +58,33 @@ Item {
     // public API
     // TODO 5.15: required property
     property var document: undefined
-    property real renderScale: 1
-    property real pageRotation: 0
-    property string searchString
+
     property string selectedText
-    property alias currentPage: navigationStack.currentPage
     function copySelectionToClipboard() {
         if (listView.currentItem !== null)
             listView.currentItem.selection.copyToClipboard()
     }
+
+    // page navigation
+    property alias currentPage: navigationStack.currentPage
     property alias backEnabled: navigationStack.backAvailable
     property alias forwardEnabled: navigationStack.forwardAvailable
-    function back() {
-        navigationStack.back()
-    }
-    function forward() {
-        navigationStack.forward()
-    }
-
-    function resetScale() {
-        root.renderScale = 1
+    function back() { navigationStack.back() }
+    function forward() { navigationStack.forward() }
+    function goToPage(page) { goToLocation(page, Qt.point(0, 0), 0) }
+    function goToLocation(page, location, zoom) {
+        if (zoom > 0)
+            root.renderScale = zoom
+        navigationStack.push(page, location, zoom)
     }
 
+    // page scaling
+    property real renderScale: 1
+    property real pageRotation: 0
+    function resetScale() { root.renderScale = 1 }
     function scaleToWidth(width, height) {
         root.renderScale = width / (listView.rot90 ? listView.firstPagePointSize.height : listView.firstPagePointSize.width)
     }
-
     function scaleToPage(width, height) {
         var windowAspect = width / height
         var pageAspect = listView.firstPagePointSize.width / listView.firstPagePointSize.height
@@ -102,14 +103,39 @@ Item {
         }
     }
 
-    function goToPage(page) {
-        goToLocation(page, Qt.point(0, 0), 0)
+    // text search
+    property alias searchString: searchModel.searchString
+    property bool searchBackEnabled: searchModel.currentResult > 0
+    property bool searchForwardEnabled: searchModel.currentResult < searchModel.matchGeometry.length - 1
+    function searchBack() {
+        if (searchModel.currentResult > 0) {
+            --searchModel.currentResult
+        } else {
+            searchModel.deferRendering = true // save time while we are searching
+            while (searchModel.currentResult <= 0) {
+                if (navigationStack.currentPage > 0)
+                    goToPage(navigationStack.currentPage - 1)
+                else
+                    goToPage(document.pageCount - 1)
+                searchModel.currentResult = searchModel.matchGeometry.length - 1
+            }
+            searchModel.deferRendering = false
+        }
     }
-
-    function goToLocation(page, location, zoom) {
-        if (zoom > 0)
-            root.renderScale = zoom
-        navigationStack.push(page, location, zoom)
+    function searchForward() {
+        if (searchModel.currentResult < searchModel.matchGeometry.length - 1) {
+            ++searchModel.currentResult
+        } else {
+            searchModel.deferRendering = true // save time while we are searching
+            while (searchModel.currentResult >= searchModel.matchGeometry.length - 1) {
+                searchModel.currentResult = 0
+                if (navigationStack.currentPage < document.pageCount - 1)
+                    goToPage(navigationStack.currentPage + 1)
+                else
+                    goToPage(0)
+            }
+            searchModel.deferRendering = false
+        }
     }
 
     id: root
@@ -133,7 +159,7 @@ Item {
             property real pageScale: image.paintedWidth / pagePointSize.width
             Image {
                 id: image
-                source: document.source
+                source: searchModel.deferRendering ? "" : document.source
                 currentFrame: index
                 asynchronous: true
                 fillMode: Image.PreserveAspectFit
@@ -152,18 +178,26 @@ Item {
             Shape {
                 anchors.fill: parent
                 opacity: 0.25
-                visible: image.status === Image.Ready
+                visible: image.status === Image.Ready && searchModel.page == index
                 ShapePath {
                     strokeWidth: 1
-                    strokeColor: "blue"
-                    fillColor: "cyan"
+                    strokeColor: "steelblue"
+                    fillColor: "lightsteelblue"
                     scale: Qt.size(paper.pageScale, paper.pageScale)
                     PathMultiline {
-                        id: searchResultBoundaries
                         paths: searchModel.matchGeometry
                     }
                 }
                 ShapePath {
+                    strokeWidth: 1
+                    strokeColor: "blue"
+                    fillColor: "cyan"
+                    scale: Qt.size(paper.pageScale, paper.pageScale)
+                    PathPolyline {
+                        path: searchModel.matchGeometry[searchModel.currentResult]
+                    }
+                }
+                ShapePath {
                     fillColor: "orange"
                     scale: Qt.size(paper.pageScale, paper.pageScale)
                     PathMultiline {
@@ -172,12 +206,6 @@ Item {
                     }
                 }
             }
-            PdfSearchModel {
-                id: searchModel
-                document: root.document
-                page: image.currentFrame
-                searchString: root.searchString
-            }
             PdfSelection {
                 id: selection
                 document: root.document
@@ -274,4 +302,12 @@ Item {
         onCurrentZoomChanged: root.renderScale = currentZoom
         // TODO deal with horizontal location (need another Flickable probably)
     }
+    PdfSearchModel {
+        id: searchModel
+        document: root.document === undefined ? null : root.document
+        page: navigationStack.currentPage
+        searchString: root.searchString
+        property int currentResult: 0
+        property bool deferRendering: false
+    }
 }