List KML contents
List the contents of a KML file.
Use case
KML files can contain a hierarchy of features, including network links to other KML content. A user may wish to traverse through the contents of KML nodes to know what data is contained within each node and, recursively, their children.
How to use the sample
The contents of the KML file are shown in a list of buttons. Select a node to zoom to that node and see its child nodes, if it has any. Not all nodes can be zoomed to (e.g. screen overlays).
How it works
- Add the KML file to the scene as a layer.
- Explore the root nodes of the
KmlDataset
recursively to create a view model.
- Each node is enabled for display at this step. KML files may include nodes that are turned off by default.
- When a node is selected, use the node's
Extent
to determine a viewpoint and set theSceneView
object's viewpoint to it.
Relevant API
- KmlContainer
- KmlDataset
- KmlDocument
- KmlFolder
- KmlGroundOverlay
- KmlLayer
- KmlNetworkLink
- KmlNode
- KmlPlacemark
- KmlScreenOverlay
Offline data
To set up the sample's offline data, see the Use offline data in the samples section of the Qt Samples repository overview.
Link | Local Location |
---|---|
ESRI test data | <userhome> /ArcGIS/Runtime/Data/kml/esri_test_data.kmz |
About the data
This is an example KML file meant to demonstrate how the ArcGIS Maps SDK for Native Apps supports several common features.
Tags
Keyhole, KML, KMZ, layers, OGC
Sample Code
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
// [WriteFile Name=ListKmlContents, Category=Layers]
// [Legal]
// Copyright 2020 Esri.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// [Legal]
#ifdef PCH_BUILD
#include "pch.hpp"
#endif // PCH_BUILD
#include "ListKmlContents.h"
#include "ArcGISTiledElevationSource.h"
#include "KmlContainer.h"
#include "KmlDataset.h"
#include "KmlLayer.h"
#include "KmlNetworkLink.h"
#include "KmlNode.h"
#include "KmlNodeListModel.h"
#include "Scene.h"
#include "SceneQuickView.h"
#include "Error.h"
#include "MapTypes.h"
#include "TaskWatcher.h"
#include "LayerListModel.h"
#include "Surface.h"
#include "ElevationSourceListModel.h"
#include "KmlViewpoint.h"
#include "Camera.h"
#include "Envelope.h"
#include "Point.h"
#include "SpatialReference.h"
#include <algorithm>
#include <QUuid>
#include <QStandardPaths>
using namespace Esri::ArcGISRuntime;
// helper method to get cross platform data path
namespace
{
QString defaultDataPath()
{
QString dataPath;
#ifdef Q_OS_IOS
dataPath = QStandardPaths::writableLocation(QStandardPaths::DocumentsLocation);
#else
dataPath = QStandardPaths::writableLocation(QStandardPaths::HomeLocation);
#endif
return dataPath;
}
} // namespace
ListKmlContents::ListKmlContents(QObject* parent /* = nullptr */):
QObject(parent),
m_scene(new Scene(BasemapStyle::ArcGISImagery, this))
{
// create a new elevation source from Terrain3D REST service
ArcGISTiledElevationSource* elevationSource = new ArcGISTiledElevationSource(
QUrl("https://elevation3d.arcgis.com/arcgis/rest/services/WorldElevation3D/Terrain3D/ImageServer"), this);
// add the elevation source to the scene to display elevation
m_scene->baseSurface()->elevationSources()->append(elevationSource);
const QString filepath = defaultDataPath() + "/ArcGIS/Runtime/Data/kml/esri_test_data.kmz";
// create new KML layer
m_kmlDataset = new KmlDataset(filepath, this);
KmlLayer* kmlLayer = new KmlLayer(m_kmlDataset, this);
m_scene->operationalLayers()->append(kmlLayer);
connect(m_kmlDataset, &KmlDataset::doneLoading, this, [this](const Error& loadError)
{
if (!loadError.isEmpty())
{
qDebug() << loadError.message() << loadError.additionalMessage();
return;
}
// recursively build tree to display KML contents
const auto nodes = m_kmlDataset->rootNodes();
for (KmlNode* node : nodes)
{
m_kmlNodesList << node;
buildTree(node);
}
// if at top node, then display children
if (!m_kmlNodesList.isEmpty() && m_kmlNodesList[0]->parentNode() == nullptr)
{
m_currentNode = m_kmlNodesList[0];
emit currentNodeChanged();
emit levelNodeNamesChanged();
}
});
}
QString ListKmlContents::getKmlNodeType(KmlNode *node)
{
if (node == nullptr)
return "";
QString type = "";
switch (node->kmlNodeType()) {
case KmlNodeType::KmlDocument:
type = "KmlDocument";
break;
case KmlNodeType::KmlFolder:
type = "KmlFolder";
break;
case KmlNodeType::KmlNetworkLink:
type = "KmlNetworkLink";
break;
case KmlNodeType::KmlPlacemark:
type = "KmlPlacemark";
break;
case KmlNodeType::KmlPhotoOverlay:
type = "KmlPhotoOverlay";
break;
case KmlNodeType::KmlGroundOverlay:
type = "KmlGroundOverlay";
break;
case KmlNodeType::KmlScreenOverlay:
type = "KmlScreenOverlay";
break;
case KmlNodeType::KmlTour:
type = "KmlTour";
break;
default:
return "";
}
return type;
}
// recursively build string to indicate node's ancestors
QStringList ListKmlContents::buildPathLabel(KmlNode* node) const
{
if (node != nullptr)
return buildPathLabel(node->parentNode()) << node->name();
else
return QStringList {};
}
void ListKmlContents::displayPreviousLevel()
{
KmlNode* parentNode = m_currentNode->parentNode();
if (parentNode == nullptr)
return;
KmlNode* grandparentNode = parentNode->parentNode();
if (grandparentNode != nullptr)
{
m_currentNode = grandparentNode;
emit currentNodeChanged();
emit labelTextChanged();
emit levelNodeNamesChanged();
}
// if grandparent node is nullptr, then at top of tree
else
{
m_currentNode = parentNode;
emit currentNodeChanged();
emit labelTextChanged();
emit levelNodeNamesChanged();
}
}
// display selected node on sceneview and show its children
void ListKmlContents::processSelectedNode(const QString& nodeName)
{
// extract the node's name from the string, formatted "name - nodeType"
QString extractedNodeName = nodeName;
if (nodeName.contains(" - "))
{
int ind = nodeName.lastIndexOf(" - ");
extractedNodeName = nodeName.left(ind);
}
// find node in the list
for (KmlNode* node : qAsConst(m_kmlNodesList))
{
if (extractedNodeName == node->name())
{
// update current node
m_currentNode = node;
emit currentNodeChanged();
emit labelTextChanged();
m_viewpoint = Viewpoint();
getViewpointFromKmlViewpoint(node);
if (m_needsAltitudeFixed)
{
getAltitudeAdjustedViewpoint(node);
}
else
{
if (!m_viewpoint.isEmpty() && !m_viewpoint.targetGeometry().isEmpty())
m_sceneView->setViewpoint(m_viewpoint);
}
// reset m_lastLevel before levelNodeNames() is called
emit levelNodeNamesChanged();
// if displaying end-nodes, change m_currentNode to first end-node for correct behavior of back button
if (noGrandchildren(m_currentNode))
{
m_currentNode = static_cast<KmlContainer*>(m_currentNode)->childNodesListModel()->at(0);
emit currentNodeChanged();
}
break;
}
}
}
void ListKmlContents::getViewpointFromKmlViewpoint(KmlNode* node)
{
const KmlViewpoint kmlViewpoint = node->viewpoint();
if (!kmlViewpoint.isEmpty())
{
// altitude adjustment is needed for all but Absolute altitude mode
m_needsAltitudeFixed = (kmlViewpoint.altitudeMode() != KmlAltitudeMode::Absolute);
switch (kmlViewpoint.type())
{
case KmlViewpointType::LookAt:
m_viewpoint = Viewpoint(kmlViewpoint.location(), Camera(kmlViewpoint.location(), kmlViewpoint.range(),
kmlViewpoint.heading(), kmlViewpoint.pitch(), kmlViewpoint.roll()));
return;
case KmlViewpointType::Camera:
m_viewpoint = Viewpoint(kmlViewpoint.location(), Camera(kmlViewpoint.location(),
kmlViewpoint.heading(), kmlViewpoint.pitch(), kmlViewpoint.roll()));
return;
default:
qWarning("Unexpected KmlViewpointType");
return;
}
}
// if viewpoint was empty, then use node's extent
const Envelope nodeExtent = node->extent();
if (nodeExtent.isValid() && !nodeExtent.isEmpty())
{
// when no altitude is specified, assume elevation needs to be adjusted
m_needsAltitudeFixed = true;
if (nodeExtent.width() == 0 && nodeExtent.height() == 0)
{
// default values: distance = 1000m, pitch = 45 degrees
m_viewpoint = Viewpoint(nodeExtent);
m_sceneView->setViewpointCameraAndWait(Camera(nodeExtent.center(), 1000, 0, 45, 0));
return;
}
else
{
// add padding to extent
double bufferDistance = qMax(nodeExtent.width(), nodeExtent.height()) / 20;
Envelope bufferedExtent = Envelope(nodeExtent.xMin() - bufferDistance, nodeExtent.yMin() - bufferDistance,
nodeExtent.xMax() + bufferDistance, nodeExtent.yMax() + bufferDistance,
nodeExtent.zMin() - bufferDistance, nodeExtent.zMax() + bufferDistance,
SpatialReference::wgs84());
m_viewpoint = Viewpoint(bufferedExtent);
}
}
else
{
// can't show viewpoint
m_needsAltitudeFixed = false;
m_viewpoint = Viewpoint();
}
}
void ListKmlContents::getAltitudeAdjustedViewpoint(KmlNode* node)
{
// assume altitude mode is clamp-to-ground if not specified
KmlAltitudeMode altMode = KmlAltitudeMode::ClampToGround;
KmlViewpoint kmlViewpoint = node->viewpoint();
if (!kmlViewpoint.isEmpty())
{
altMode = kmlViewpoint.altitudeMode();
}
// if altitude mode is Absolute, viewpoint doesn't need adjustment
if (altMode == KmlAltitudeMode::Absolute)
{
m_sceneView->setViewpoint(m_viewpoint);
return;
}
const Envelope lookAtExtent = geometry_cast<Envelope>(m_viewpoint.targetGeometry());
const Point lookAtPoint = geometry_cast<Point>(m_viewpoint.targetGeometry());
if (lookAtExtent.isValid())
{
m_scene->baseSurface()->locationToElevation(lookAtExtent.center());
}
else if (lookAtPoint.isValid())
{
m_scene->baseSurface()->locationToElevation(lookAtPoint);
}
}
// recursively build list of all KML nodes
void ListKmlContents::buildTree(KmlNode* parentNode)
{
auto addNode = [this](KmlNode* node)
{
// some nodes have default visibility set to false
node->setVisible(true);
m_kmlNodesList << node;
buildTree(node);
};
if (KmlContainer* container = dynamic_cast<KmlContainer*>(parentNode))
{
const KmlNodeListModel& childNodes = *container->childNodesListModel();
std::for_each(std::begin(childNodes), std::end(childNodes), addNode);
}
else if (KmlNetworkLink* networkLink = dynamic_cast<KmlNetworkLink*>(parentNode))
{
const QList<KmlNode*> childNodes = networkLink->childNodes();
std::for_each(std::begin(childNodes), std::end(childNodes), addNode);
}
}
ListKmlContents::~ListKmlContents() = default;
void ListKmlContents::init()
{
// Register classes for QML
qmlRegisterType<SceneQuickView>("Esri.Samples", 1, 0, "SceneView");
qmlRegisterType<ListKmlContents>("Esri.Samples", 1, 0, "ListKmlContentsSample");
}
SceneQuickView* ListKmlContents::sceneView() const
{
return m_sceneView;
}
// Set the view (created in QML)
void ListKmlContents::setSceneView(SceneQuickView* sceneView)
{
if (!sceneView || sceneView == m_sceneView)
return;
m_sceneView = sceneView;
m_sceneView->setArcGISScene(m_scene);
connect(m_scene->baseSurface(), &Surface::locationToElevationCompleted, this, [this](const QUuid&, double elevation)
{
// assume altitude mode is clamp-to-ground if not specified
KmlAltitudeMode altMode = KmlAltitudeMode::ClampToGround;
KmlViewpoint kmlViewpoint = m_currentNode->viewpoint();
if (!kmlViewpoint.isEmpty())
{
altMode = kmlViewpoint.altitudeMode();
}
// if altitude mode is Absolute, viewpoint doesn't need adjustment
if (altMode == KmlAltitudeMode::Absolute)
return;
const Envelope lookAtExtent = geometry_cast<Envelope>(m_viewpoint.targetGeometry());
const Point lookAtPoint = geometry_cast<Point>(m_viewpoint.targetGeometry());
if (lookAtExtent.isValid())
{
Envelope target;
if (altMode == KmlAltitudeMode::ClampToGround)
{
// if depth of extent is 0, add 100m to the elevation to get zMax
if (lookAtExtent.depth() == 0)
{
target = Envelope(lookAtExtent.xMin(), lookAtExtent.yMin(),
lookAtExtent.xMax(), lookAtExtent.yMax(),
elevation, elevation + 100,
lookAtExtent.spatialReference());
}
else
{
target = Envelope(lookAtExtent.xMin(), lookAtExtent.yMin(),
lookAtExtent.xMax(), lookAtExtent.yMax(),
// set the camera slightly above the placemark by adding one meter
elevation, lookAtExtent.depth() + elevation + 1,
lookAtExtent.spatialReference());
}
}
else
{
target = Envelope(lookAtExtent.xMin(), lookAtExtent.yMin(),
lookAtExtent.xMax(), lookAtExtent.yMax(),
lookAtExtent.zMin() + elevation, lookAtExtent.zMax() + elevation,
lookAtExtent.spatialReference());
}
// if node has viewpoint specified, return adjusted geometry with adjusted camera
if (!kmlViewpoint.isEmpty())
{
m_sceneView->setViewpointCameraAndWait(m_viewpoint.camera().elevate(elevation));
m_viewpoint = Viewpoint(target);
m_sceneView->setViewpoint(m_viewpoint);
return;
}
else
{
m_viewpoint = Viewpoint(target);
m_sceneView->setViewpoint(m_viewpoint);
return;
}
}
else if (lookAtPoint.isValid())
{
Point target;
if (altMode == KmlAltitudeMode::ClampToGround)
{
target = Point(lookAtPoint.x(), lookAtPoint.y(), elevation, lookAtPoint.spatialReference());
}
else
{
target = Point(lookAtPoint.x(), lookAtPoint.y(), lookAtPoint.z() + elevation, lookAtPoint.spatialReference());
}
// set the viewpoint using the adjusted target
if (!kmlViewpoint.isEmpty())
{
m_sceneView->setViewpointCameraAndWait(m_viewpoint.camera().elevate(elevation));
m_viewpoint = Viewpoint(target);
m_sceneView->setViewpoint(m_viewpoint);
return;
}
else
{
// use default values to set camera: distance = 1000m, pitch = 45 degrees
m_viewpoint = Viewpoint(target);
m_sceneView->setViewpoint(m_viewpoint);
m_sceneView->setViewpointCameraAndWait(Camera(target, 1000, 0, 45, 0));
return;
}
}
});
emit sceneViewChanged();
}
QStringList ListKmlContents::levelNodeNames()
{
if (m_currentNode == nullptr)
return {};
QStringList nodeNames = {};
// if node is not a container, m_levelNodeNames will be unchanged
if (KmlContainer* container = dynamic_cast<KmlContainer*>(m_currentNode))
{
// for current level, get names of child nodes
for (KmlNode* node: *(container->childNodesListModel()))
{
QString str = node->name() + " - " + getKmlNodeType(node);
// if node has children, add ">" to indicate further levels
if (!node->children().isEmpty())
{
str.append(" >");
}
nodeNames << str;
}
m_levelNodeNames = nodeNames;
}
return m_levelNodeNames;
}
bool ListKmlContents::noGrandchildren(KmlNode *currentNode) const
{
bool hasNoGrandchildren = false;
if (KmlContainer* container = dynamic_cast<KmlContainer*>(currentNode))
{
hasNoGrandchildren = true;
// for current level, get names of child nodes
for (KmlNode* node: *(container->childNodesListModel()))
{
// if node has children, add ">" to indicate further levels
if (!node->children().isEmpty())
{
hasNoGrandchildren = false;
}
}
}
return hasNoGrandchildren;
}
QString ListKmlContents::labelText() const
{
return buildPathLabel(m_currentNode).join(" > ");
}
bool ListKmlContents::isTopLevel() const
{
if (m_currentNode == nullptr)
return true;
else if (m_currentNode->parentNode() == nullptr)
return true;
else if (m_currentNode->name() == "")
return true;
else
return false;
}