1 // panel_io.cxx - I/O for 2D panel.
3 // Written by David Megginson, started January 2000.
5 // This program is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU General Public License as
7 // published by the Free Software Foundation; either version 2 of the
8 // License, or (at your option) any later version.
10 // This program is distributed in the hope that it will be useful, but
11 // WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // General Public License for more details.
15 // You should have received a copy of the GNU General Public License
16 // along with this program; if not, write to the Free Software
17 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 #include <string.h> // for strcmp()
31 #include <simgear/compiler.h>
32 #include <simgear/structure/exception.hxx>
33 #include <simgear/debug/logstream.hxx>
34 #include <simgear/misc/sg_path.hxx>
35 #include <simgear/props/props.hxx>
41 #include <Main/globals.hxx>
42 #include <Main/fg_props.hxx>
46 // #include "panel.hxx"
47 #include "panel_io.hxx"
48 #include <Instrumentation/KLN89/kln89.hxx>
51 #include "built_in/FGMagRibbon.hxx"
53 SG_USING_STD(istream);
54 SG_USING_STD(ifstream);
59 ////////////////////////////////////////////////////////////////////////
60 // Read and construct a panel.
62 // The panel is specified as a regular property list, and each of the
63 // instruments is its own, separate property list (and thus, a separate
64 // XML document). The functions in this section read in the files
65 // as property lists, then extract properties to set up the panel
68 // A panel contains zero or more instruments.
70 // An instrument contains one or more layers and zero or more actions.
72 // A layer contains zero or more transformations.
74 // Some special types of layers also contain other objects, such as
75 // chunks of text or other layers.
77 // There are currently four types of layers:
79 // 1. Textured Layer (type="texture"), the default
80 // 2. Text Layer (type="text")
81 // 3. Switch Layer (type="switch")
82 // 4. Built-in Layer (type="built-in", must also specify class)
84 // The only built-in layer so far is the ribbon for the magnetic compass
85 // (class="compass-ribbon").
87 // There are three types of actions:
89 // 1. Adjust (type="adjust"), the default
90 // 2. Swap (type="swap")
91 // 3. Toggle (type="toggle")
93 // There are three types of transformations:
95 // 1. X shift (type="x-shift"), the default
96 // 2. Y shift (type="y-shift")
97 // 3. Rotation (type="rotation")
99 // Each of these may be associated with a property, so that a needle
100 // will rotate with the airspeed, for example, or may have a fixed
101 // floating-point value.
102 ////////////////////////////////////////////////////////////////////////
106 * Read a cropped texture from the instrument's property list.
108 * The x1 and y1 properties give the starting position of the texture
109 * (between 0.0 and 1.0), and the the x2 and y2 properties give the
110 * ending position. For example, to use the bottom-left quarter of a
111 * texture, x1=0.0, y1=0.0, x2=0.5, y2=0.5.
113 static FGCroppedTexture
114 readTexture (const SGPropertyNode * node)
116 FGCroppedTexture texture(node->getStringValue("path"),
117 node->getFloatValue("x1"),
118 node->getFloatValue("y1"),
119 node->getFloatValue("x2", 1.0),
120 node->getFloatValue("y2", 1.0));
121 SG_LOG(SG_COCKPIT, SG_DEBUG, "Read texture " << node->getName());
127 * Test for a condition in the current node.
130 ////////////////////////////////////////////////////////////////////////
131 // Read a condition and use it if necessary.
132 ////////////////////////////////////////////////////////////////////////
135 readConditions (SGConditional *component, const SGPropertyNode *node)
137 const SGPropertyNode * conditionNode = node->getChild("condition");
138 if (conditionNode != 0)
139 // The top level is implicitly AND
140 component->setCondition(sgReadCondition(globals->get_props(),
146 * Read an action from the instrument's property list.
148 * The action will be performed when the user clicks a mouse button
149 * within the specified region of the instrument. Actions always work
150 * by modifying the value of a property (see the SGPropertyNode
153 * The following action types are defined:
155 * "adjust" - modify the value of a floating-point property by
156 * the increment specified. This is the default.
158 * "swap" - swap the values of two-floating-point properties.
160 * "toggle" - toggle the value of a boolean property between true and
163 * For the adjust action, it is possible to specify an increment
164 * (use a negative number for a decrement), a minimum allowed value,
165 * a maximum allowed value, and a flag to indicate whether the value
166 * should freeze or wrap-around when it reachs the minimum or maximum.
168 * The action will be scaled automatically if the instrument is not
169 * being drawn at its regular size.
171 static FGPanelAction *
172 readAction (const SGPropertyNode * node, float w_scale, float h_scale)
174 string name = node->getStringValue("name");
176 int button = node->getIntValue("button");
177 int x = int(node->getIntValue("x") * w_scale);
178 int y = int(node->getIntValue("y") * h_scale);
179 int w = int(node->getIntValue("w") * w_scale);
180 int h = int(node->getIntValue("h") * h_scale);
181 bool repeatable = node->getBoolValue("repeatable", true);
183 FGPanelAction * action = new FGPanelAction(button, x, y, w, h, repeatable);
185 vector<SGPropertyNode_ptr>bindings = node->getChildren("binding");
186 SGPropertyNode * dest = fgGetNode("/sim/bindings/panel", true);
188 SGPropertyNode *binding;
190 for (i = 0; i < bindings.size(); i++) {
191 SG_LOG(SG_INPUT, SG_INFO, "Reading binding "
192 << bindings[i]->getStringValue("command"));
195 while (dest->getChild("binding", j))
198 binding = dest->getChild("binding", j, true);
199 copyProperties(bindings[i], binding);
200 action->addBinding(new FGBinding(binding), 0);
203 if (node->hasChild("mod-up")) {
204 bindings = node->getChild("mod-up")->getChildren("binding");
205 for (i = 0; i < bindings.size(); i++) {
207 while (dest->getChild("binding", j))
210 binding = dest->getChild("binding", j, true);
211 copyProperties(bindings[i], binding);
212 action->addBinding(new FGBinding(binding), 1);
216 readConditions(action, node);
222 * Read a transformation from the instrument's property list.
224 * The panel module uses the transformations to slide or spin needles,
225 * knobs, and other indicators, and to place layers in the correct
226 * positions. Every layer starts centered exactly on the x,y co-ordinate,
227 * and many layers need to be moved or rotated simply to display the
228 * instrument correctly.
230 * There are three types of transformations:
232 * "x-shift" - move the layer horizontally.
234 * "y-shift" - move the layer vertically.
236 * "rotation" - rotate the layer.
238 * Each transformation may have a fixed offset, and may also have
239 * a floating-point property value to add to the offset. The
240 * floating-point property may be clamped to a minimum and/or
241 * maximum range and scaled (after clamping).
243 * Note that because of the way OpenGL works, transformations will
244 * appear to be applied backwards.
246 static FGPanelTransformation *
247 readTransformation (const SGPropertyNode * node, float w_scale, float h_scale)
249 FGPanelTransformation * t = new FGPanelTransformation;
251 string name = node->getName();
252 string type = node->getStringValue("type");
253 string propName = node->getStringValue("property", "");
254 SGPropertyNode * target = 0;
257 SG_LOG( SG_COCKPIT, SG_INFO,
258 "No type supplied for transformation " << name
259 << " assuming \"rotation\"" );
263 if (!propName.empty()) {
264 target = fgGetNode(propName.c_str(), true);
268 t->min = node->getFloatValue("min", -9999999);
269 t->max = node->getFloatValue("max", 99999999);
270 t->has_mod = node->hasChild("modulator");
272 t->mod = node->getFloatValue("modulator");
273 t->factor = node->getFloatValue("scale", 1.0);
274 t->offset = node->getFloatValue("offset", 0.0);
276 // Check for an interpolation table
277 const SGPropertyNode * trans_table = node->getNode("interpolation");
278 if (trans_table != 0) {
279 SG_LOG( SG_COCKPIT, SG_INFO, "Found interpolation table with "
280 << trans_table->nChildren() << "children" );
281 t->table = new SGInterpTable();
282 for(int i = 0; i < trans_table->nChildren(); i++) {
283 const SGPropertyNode * node = trans_table->getChild(i);
284 if (!strcmp(node->getName(), "entry")) {
285 double ind = node->getDoubleValue("ind", 0.0);
286 double dep = node->getDoubleValue("dep", 0.0);
287 SG_LOG( SG_COCKPIT, SG_INFO, "Adding interpolation entry "
288 << ind << "==>" << dep );
289 t->table->addEntry(ind, dep);
291 SG_LOG( SG_COCKPIT, SG_INFO, "Skipping " << node->getName()
292 << " in interpolation" );
299 // Move the layer horizontally.
300 if (type == "x-shift") {
301 t->type = FGPanelTransformation::XSHIFT;
302 // t->min *= w_scale; //removed by Martin Dressler
303 // t->max *= w_scale; //removed by Martin Dressler
304 t->offset *= w_scale;
305 t->factor *= w_scale; //Added by Martin Dressler
308 // Move the layer vertically.
309 else if (type == "y-shift") {
310 t->type = FGPanelTransformation::YSHIFT;
311 //t->min *= h_scale; //removed
312 //t->max *= h_scale; //removed
313 t->offset *= h_scale;
314 t->factor *= h_scale; //Added
317 // Rotate the layer. The rotation
318 // is in degrees, and does not need
319 // to scale with the instrument size.
320 else if (type == "rotation") {
321 t->type = FGPanelTransformation::ROTATION;
325 SG_LOG( SG_COCKPIT, SG_ALERT, "Unrecognized transformation type " << type );
330 readConditions(t, node);
331 SG_LOG( SG_COCKPIT, SG_DEBUG, "Read transformation " << name );
337 * Read a chunk of text from the instrument's property list.
339 * A text layer consists of one or more chunks of text. All chunks
340 * share the same font size and color (and eventually, font), but
341 * each can come from a different source. There are three types of
344 * "literal" - a literal text string (the default)
346 * "text-value" - the current value of a string property
348 * "number-value" - the current value of a floating-point property.
350 * All three may also include a printf-style format string.
353 readTextChunk (const SGPropertyNode * node)
355 FGTextLayer::Chunk * chunk;
356 string name = node->getStringValue("name");
357 string type = node->getStringValue("type");
358 string format = node->getStringValue("format");
360 // Default to literal text.
362 SG_LOG( SG_COCKPIT, SG_INFO, "No type provided for text chunk " << name
363 << " assuming \"literal\"");
367 // A literal text string.
368 if (type == "literal") {
369 string text = node->getStringValue("text");
370 chunk = new FGTextLayer::Chunk(text, format);
373 // The value of a string property.
374 else if (type == "text-value") {
375 SGPropertyNode * target =
376 fgGetNode(node->getStringValue("property"), true);
377 chunk = new FGTextLayer::Chunk(FGTextLayer::TEXT_VALUE, target, format);
380 // The value of a float property.
381 else if (type == "number-value") {
382 string propName = node->getStringValue("property");
383 float scale = node->getFloatValue("scale", 1.0);
384 float offset = node->getFloatValue("offset", 0.0);
385 bool truncation = node->getBoolValue("truncate", false);
386 SGPropertyNode * target = fgGetNode(propName.c_str(), true);
387 chunk = new FGTextLayer::Chunk(FGTextLayer::DOUBLE_VALUE, target,
388 format, scale, offset, truncation);
393 SG_LOG( SG_COCKPIT, SG_ALERT, "Unrecognized type " << type
394 << " for text chunk " << name );
398 readConditions(chunk, node);
404 * Read a single layer from an instrument's property list.
406 * Each instrument consists of one or more layers stacked on top
407 * of each other; the lower layers show through only where the upper
408 * layers contain an alpha component. Each layer can be moved
409 * horizontally and vertically and rotated using transformations.
411 * This module currently recognizes four kinds of layers:
413 * "texture" - a layer containing a texture (the default)
415 * "text" - a layer containing text
417 * "switch" - a layer that switches between two other layers
418 * based on the current value of a boolean property.
420 * "built-in" - a hard-coded layer supported by C++ code in FlightGear.
422 * Currently, the only built-in layer class is "compass-ribbon".
424 static FGInstrumentLayer *
425 readLayer (const SGPropertyNode * node, float w_scale, float h_scale)
427 FGInstrumentLayer * layer = NULL;
428 string name = node->getStringValue("name");
429 string type = node->getStringValue("type");
430 int w = node->getIntValue("w", -1);
431 int h = node->getIntValue("h", -1);
433 w = int(w * w_scale);
435 h = int(h * h_scale);
439 SG_LOG( SG_COCKPIT, SG_INFO,
440 "No type supplied for layer " << name
441 << " assuming \"texture\"" );
446 // A textured instrument layer.
447 if (type == "texture") {
448 FGCroppedTexture texture = readTexture(node->getNode("texture"));
449 layer = new FGTexturedLayer(texture, w, h);
452 // A group of sublayers.
453 else if (type == "group") {
454 layer = new FGGroupLayer();
455 for (int i = 0; i < node->nChildren(); i++) {
456 const SGPropertyNode * child = node->getChild(i);
457 if (!strcmp(child->getName(), "layer"))
458 ((FGGroupLayer *)layer)->addLayer(readLayer(child, w_scale, h_scale));
463 // A textual instrument layer.
464 else if (type == "text") {
465 FGTextLayer * tlayer = new FGTextLayer(w, h); // FIXME
467 // Set the text color.
468 float red = node->getFloatValue("color/red", 0.0);
469 float green = node->getFloatValue("color/green", 0.0);
470 float blue = node->getFloatValue("color/blue", 0.0);
471 tlayer->setColor(red, green, blue);
473 // Set the point size.
474 float pointSize = node->getFloatValue("point-size", 10.0) * w_scale;
475 tlayer->setPointSize(pointSize);
478 string fontName = node->getStringValue("font", "default");
479 tlayer->setFontName(fontName);
481 const SGPropertyNode * chunk_group = node->getNode("chunks");
482 if (chunk_group != 0) {
483 int nChunks = chunk_group->nChildren();
484 for (int i = 0; i < nChunks; i++) {
485 const SGPropertyNode * node = chunk_group->getChild(i);
486 if (!strcmp(node->getName(), "chunk")) {
487 FGTextLayer::Chunk * chunk = readTextChunk(node);
489 tlayer->addChunk(chunk);
491 SG_LOG( SG_COCKPIT, SG_INFO, "Skipping " << node->getName()
499 // A switch instrument layer.
500 else if (type == "switch") {
501 layer = new FGSwitchLayer();
502 for (int i = 0; i < node->nChildren(); i++) {
503 const SGPropertyNode * child = node->getChild(i);
504 if (!strcmp(child->getName(), "layer"))
505 ((FGGroupLayer *)layer)->addLayer(readLayer(child, w_scale, h_scale));
509 // A built-in instrument layer.
510 else if (type == "built-in") {
511 string layerclass = node->getStringValue("class");
513 if (layerclass == "mag-ribbon") {
514 layer = new FGMagRibbon(w, h);
517 else if (layerclass.empty()) {
518 SG_LOG( SG_COCKPIT, SG_ALERT, "No class provided for built-in layer "
524 SG_LOG( SG_COCKPIT, SG_ALERT, "Unknown built-in layer class "
532 SG_LOG( SG_COCKPIT, SG_ALERT, "Unrecognized layer type " << type );
538 // Get the transformations for each layer.
540 const SGPropertyNode * trans_group = node->getNode("transformations");
541 if (trans_group != 0) {
542 int nTransformations = trans_group->nChildren();
543 for (int i = 0; i < nTransformations; i++) {
544 const SGPropertyNode * node = trans_group->getChild(i);
545 if (!strcmp(node->getName(), "transformation")) {
546 FGPanelTransformation * t = readTransformation(node, w_scale, h_scale);
548 layer->addTransformation(t);
550 SG_LOG( SG_COCKPIT, SG_INFO, "Skipping " << node->getName()
551 << " in transformations" );
556 readConditions(layer, node);
557 SG_LOG( SG_COCKPIT, SG_DEBUG, "Read layer " << name );
563 * Read an instrument from a property list.
565 * The instrument consists of a preferred width and height
566 * (the panel may override these), together with a list of layers
567 * and a list of actions to be performed when the user clicks
568 * the mouse over the instrument. All co-ordinates are relative
569 * to the instrument's position, so instruments are fully relocatable;
570 * likewise, co-ordinates for actions and transformations will be
571 * scaled automatically if the instrument is not at its preferred size.
573 static FGPanelInstrument *
574 readInstrument (const SGPropertyNode * node)
576 const string name = node->getStringValue("name");
577 int x = node->getIntValue("x", -1);
578 int y = node->getIntValue("y", -1);
579 int real_w = node->getIntValue("w", -1);
580 int real_h = node->getIntValue("h", -1);
581 int w = node->getIntValue("w-base", -1);
582 int h = node->getIntValue("h-base", -1);
584 if (x == -1 || y == -1) {
585 SG_LOG( SG_COCKPIT, SG_ALERT,
586 "x and y positions must be specified and > 0" );
593 w_scale = float(real_w) / float(w);
597 h_scale = float(real_h) / float(h);
601 SG_LOG( SG_COCKPIT, SG_DEBUG, "Reading instrument " << name );
603 FGLayeredInstrument * instrument =
604 new FGLayeredInstrument(x, y, w, h);
607 // Get the actions for the instrument.
609 const SGPropertyNode * action_group = node->getNode("actions");
610 if (action_group != 0) {
611 int nActions = action_group->nChildren();
612 for (int i = 0; i < nActions; i++) {
613 const SGPropertyNode * node = action_group->getChild(i);
614 if (!strcmp(node->getName(), "action")) {
615 FGPanelAction * action = readAction(node, w_scale, h_scale);
617 instrument->addAction(action);
619 SG_LOG( SG_COCKPIT, SG_INFO, "Skipping " << node->getName()
626 // Get the layers for the instrument.
628 const SGPropertyNode * layer_group = node->getNode("layers");
629 if (layer_group != 0) {
630 int nLayers = layer_group->nChildren();
631 for (int i = 0; i < nLayers; i++) {
632 const SGPropertyNode * node = layer_group->getChild(i);
633 if (!strcmp(node->getName(), "layer")) {
634 FGInstrumentLayer * layer = readLayer(node, w_scale, h_scale);
636 instrument->addLayer(layer);
638 SG_LOG( SG_COCKPIT, SG_INFO, "Skipping " << node->getName()
644 readConditions(instrument, node);
645 SG_LOG( SG_COCKPIT, SG_DEBUG, "Done reading instrument " << name );
651 * Construct the panel from a property tree.
654 readPanel (const SGPropertyNode * root)
656 SG_LOG( SG_COCKPIT, SG_INFO, "Reading properties for panel " <<
657 root->getStringValue("name", "[Unnamed Panel]") );
659 FGPanel * panel = new FGPanel();
660 panel->setWidth(root->getIntValue("w", 1024));
661 panel->setHeight(root->getIntValue("h", 443));
664 // Grab the visible external viewing area, default to
666 panel->setViewHeight(root->getIntValue("view-height",
667 768 - panel->getHeight() + 2));
670 // Grab the panel's initial offsets, default to 0, 0.
672 if (!fgHasNode("/sim/panel/x-offset"))
673 fgSetInt("/sim/panel/x-offset", root->getIntValue("x-offset", 0));
675 // conditional removed by jim wilson to allow panel xml code
676 // with y-offset defined to work...
677 if (!fgHasNode("/sim/panel/y-offset"))
678 fgSetInt("/sim/panel/y-offset", root->getIntValue("y-offset", 0));
681 // Assign the background texture, if any, or a bogus chequerboard.
683 string bgTexture = root->getStringValue("background");
684 if (bgTexture.empty())
686 panel->setBackground(FGTextureManager::createTexture(bgTexture.c_str()));
687 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << bgTexture );
690 // Get multibackground if any...
692 string mbgTexture = root->getStringValue("multibackground[0]");
693 if (!mbgTexture.empty()) {
694 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 0);
695 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
697 mbgTexture = root->getStringValue("multibackground[1]");
698 if (mbgTexture.empty())
700 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 1);
701 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
703 mbgTexture = root->getStringValue("multibackground[2]");
704 if (mbgTexture.empty())
706 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 2);
707 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
709 mbgTexture = root->getStringValue("multibackground[3]");
710 if (mbgTexture.empty())
712 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 3);
713 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
715 mbgTexture = root->getStringValue("multibackground[4]");
716 if (mbgTexture.empty())
718 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 4);
719 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
721 mbgTexture = root->getStringValue("multibackground[5]");
722 if (mbgTexture.empty())
724 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 5);
725 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
727 mbgTexture = root->getStringValue("multibackground[6]");
728 if (mbgTexture.empty())
730 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 6);
731 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
733 mbgTexture = root->getStringValue("multibackground[7]");
734 if (mbgTexture.empty())
736 panel->setMultiBackground(FGTextureManager::createTexture(mbgTexture.c_str()), 7);
737 SG_LOG( SG_COCKPIT, SG_INFO, "Set background texture to " << mbgTexture );
744 // Create each instrument.
746 SG_LOG( SG_COCKPIT, SG_INFO, "Reading panel instruments" );
747 const SGPropertyNode * instrument_group = root->getChild("instruments");
748 if (instrument_group != 0) {
749 int nInstruments = instrument_group->nChildren();
750 for (int i = 0; i < nInstruments; i++) {
751 const SGPropertyNode * node = instrument_group->getChild(i);
752 if (!strcmp(node->getName(), "instrument")) {
753 FGPanelInstrument * instrument = readInstrument(node);
755 panel->addInstrument(instrument);
756 } else if(!strcmp(node->getName(), "special-instrument")) {
757 //cout << "Special instrument found in instruments section!\n";
758 const string name = node->getStringValue("name");
759 if(name == "KLN89 GPS") {
760 //cout << "Special instrument is KLN89\n";
762 int x = node->getIntValue("x", -1);
763 int y = node->getIntValue("y", -1);
764 int real_w = node->getIntValue("w", -1);
765 int real_h = node->getIntValue("h", -1);
766 int w = node->getIntValue("w-base", -1);
767 int h = node->getIntValue("h-base", -1);
769 if (x == -1 || y == -1) {
770 SG_LOG( SG_COCKPIT, SG_ALERT,
771 "x and y positions must be specified and > 0" );
778 w_scale = float(real_w) / float(w);
782 h_scale = float(real_h) / float(h);
786 SG_LOG( SG_COCKPIT, SG_DEBUG, "Reading instrument " << name );
788 // Warning - hardwired size!!!
789 RenderArea2D* instrument = new RenderArea2D(158, 40, 158, 40, x, y);
790 // FIXME: shift-F3 (panel reload) kill's us here due to duplicate subsystem!
791 KLN89* gps = new KLN89(instrument);
792 panel->addInstrument(gps);
793 globals->add_subsystem("kln89", gps);
794 //gps->init(); // init seems to get called automagically.
796 SG_LOG( SG_COCKPIT, SG_WARN, "Unknown special instrument found" );
799 SG_LOG( SG_COCKPIT, SG_INFO, "Skipping " << node->getName()
800 << " in instruments section" );
804 SG_LOG( SG_COCKPIT, SG_INFO, "Done reading panel instruments" );
808 // Return the new panel.
815 * Read a panel from a property list.
817 * Each panel instrument will appear in its own, separate
818 * property list. The top level simply names the panel and
819 * places the instruments in their appropriate locations (and
820 * optionally resizes them if necessary).
822 * Returns 0 if the read fails for any reason.
825 fgReadPanel (istream &input)
830 readProperties(input, &root);
831 } catch (const sg_exception &e) {
832 guiErrorMessage("Error reading panel: ", e);
835 return readPanel(&root);
840 * Read a panel from a property list.
842 * This function opens a stream to a file, then invokes the
843 * main fgReadPanel() function.
846 fgReadPanel (const string &relative_path)
848 SGPath path(globals->get_fg_root());
849 path.append(relative_path);
853 readProperties(path.str(), &root);
854 } catch (const sg_exception &e) {
855 guiErrorMessage("Error reading panel: ", e);
858 return readPanel(&root);
863 // end of panel_io.cxx