add tabbed brush editor with Tip Shape, Paint, and Behaviors tabs

.gitignore

@@ -16,3 +16,4 @@
 .cxx
 local.properties
 ink-proto/bin/
+gradle/gradle-daemon-jvm.properties

app/src/main/java/com/example/cahier/developer/brushdesigner/ui/BehaviorsTab.kt

@@ -0,0 +1,284 @@
+/*
+ * Copyright 2026 Google LLC. All rights reserved.
+ *
+ * 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.
+ */
+
+package com.example.cahier.developer.brushdesigner.ui
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.Button
+import androidx.compose.material3.FilledTonalButton
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.unit.dp
+import com.example.cahier.R
+import com.example.cahier.developer.brushdesigner.viewmodel.PrefabBehaviors
+import ink.proto.BrushBehavior
+import ink.proto.BrushFamily as ProtoBrushFamily
+
+/**
+ * Tab 2: Dynamics & Behaviors controls — editable behavior stack with nested
+ * node graph editor, standard dynamics presets, and advanced dynamics presets.
+ *
+ * Uses [EditableListWidget] for managing behaviors (outer list) and nodes
+ * within each behavior (inner nested list), with [NodeEditor] for
+ * type-specific node editing.
+ *
+ * Stateless: receives data and callbacks, does not access ViewModel.
+ */
+@Composable
+internal fun BehaviorsTabContent(
+    activeProto: ProtoBrushFamily,
+    selectedCoatIndex: Int,
+    onUpdateBehaviors: (List<BrushBehavior>) -> Unit,
+    onClearBehaviors: () -> Unit,
+    onAddBehavior: (List<BrushBehavior.Node>) -> Unit,
+) {
+    val behaviors = activeProto
+        .coatsList.getOrNull(selectedCoatIndex)?.tip?.behaviorsList
+        ?: emptyList()
+
+    Text(
+        stringResource(R.string.brush_designer_dynamics_behaviors),
+        style = MaterialTheme.typography.titleMedium,
+        modifier = Modifier.padding(top = 8.dp)
+    )
+
+    EditableListWidget(
+        title = stringResource(R.string.brush_designer_behavior_stack),
+        items = behaviors,
+        defaultItem = BrushBehavior.newBuilder()
+            .addNodes(
+                BrushBehavior.Node.newBuilder().setSourceNode(
+                    BrushBehavior.SourceNode.newBuilder()
+                        .setSource(BrushBehavior.Source.SOURCE_NORMALIZED_PRESSURE)
+                        .setSourceValueRangeStart(0f)
+                        .setSourceValueRangeEnd(1f)
+                        .setSourceOutOfRangeBehavior(
+                            BrushBehavior.OutOfRange.OUT_OF_RANGE_CLAMP
+                        )
+                )
+            )
+            .addNodes(
+                BrushBehavior.Node.newBuilder().setTargetNode(
+                    BrushBehavior.TargetNode.newBuilder()
+                        .setTarget(BrushBehavior.Target.TARGET_SIZE_MULTIPLIER)
+                        .setTargetModifierRangeStart(0.5f)
+                        .setTargetModifierRangeEnd(1.5f)
+                )
+            )
+            .build(),
+        onItemsChanged = onUpdateBehaviors,
+        itemHeader = { behavior ->
+            val source = behavior.nodesList
+                .find { it.hasSourceNode() }
+                ?.sourceNode?.source?.name?.replace("SOURCE_", "")
+                ?: "INPUT"
+            val target = behavior.nodesList
+                .find { it.hasTargetNode() }
+                ?.targetNode?.target?.name?.replace("TARGET_", "")
+                ?: "OUTPUT"
+            "$source ➔ $target"
+        },
+        editorContent = { behavior, onBehaviorChanged ->
+            BehaviorNodeGraphEditor(
+                behavior = behavior,
+                onBehaviorChanged = onBehaviorChanged
+            )
+        }
+    )
+
+    Spacer(modifier = Modifier.height(16.dp))
+    HorizontalDivider()
+    Spacer(modifier = Modifier.height(8.dp))
+
+    StandardDynamicsSection(onAddBehavior = onAddBehavior)
+
+    Spacer(modifier = Modifier.height(16.dp))
+
+    AdvancedDynamicsSection(
+        onAddBehavior = onAddBehavior
+    )
+}
+
+/**
+ * Nested node graph editor for a single [BrushBehavior].
+ * Uses a nested [EditableListWidget] to manage the ordered list of nodes.
+ */
+@Composable
+private fun BehaviorNodeGraphEditor(
+    behavior: BrushBehavior,
+    onBehaviorChanged: (BrushBehavior) -> Unit
+) {
+    Text(
+        stringResource(R.string.brush_designer_nodes_in_behavior),
+        style = MaterialTheme.typography.labelLarge
+    )
+
+    EditableListWidget(
+        title = "",
+        items = behavior.nodesList,
+        defaultItem = BrushBehavior.Node.newBuilder()
+            .setConstantNode(
+                BrushBehavior.ConstantNode.newBuilder().setValue(1f)
+            )
+            .build(),
+        onItemsChanged = { newNodes ->
+            onBehaviorChanged(
+                behavior.toBuilder().clearNodes().addAllNodes(newNodes).build()
+            )
+        },
+        itemHeader = { node ->
+            node.nodeCase.name.replace("_NODE", "")
+        },
+        editorContent = { node, onNodeChanged ->
+            NodeEditor(node = node, onNodeChanged = onNodeChanged)
+        }
+    )
+}
+
+@Composable
+private fun StandardDynamicsSection(
+    onAddBehavior: (List<BrushBehavior.Node>) -> Unit
+) {
+    Text(
+        stringResource(R.string.brush_designer_standard_dynamics),
+        style = MaterialTheme.typography.labelLarge
+    )
+    Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+        Row(horizontalArrangement = Arrangement.spacedBy(8.dp)) {
+            Button(modifier = Modifier.weight(1f), onClick = {
+                val s = BrushBehavior.Node.newBuilder().setSourceNode(
+                    BrushBehavior.SourceNode.newBuilder()
+                        .setSource(BrushBehavior.Source.SOURCE_NORMALIZED_PRESSURE)
+                        .setSourceValueRangeStart(0f).setSourceValueRangeEnd(1f)
+                        .setSourceOutOfRangeBehavior(
+                            BrushBehavior.OutOfRange.OUT_OF_RANGE_CLAMP
+                        )
+                ).build()
+                val t = BrushBehavior.Node.newBuilder().setTargetNode(
+                    BrushBehavior.TargetNode.newBuilder()
+                        .setTarget(BrushBehavior.Target.TARGET_SIZE_MULTIPLIER)
+                        .setTargetModifierRangeStart(0.5f).setTargetModifierRangeEnd(1.5f)
+                ).build()
+                onAddBehavior(listOf(s, t))
+            }) { Text(stringResource(R.string.brush_designer_pressure_size)) }
+
+            Button(modifier = Modifier.weight(1f), onClick = {
+                val s = BrushBehavior.Node.newBuilder().setSourceNode(
+                    BrushBehavior.SourceNode.newBuilder()
+                        .setSource(
+                            BrushBehavior.Source
+                                .SOURCE_SPEED_IN_MULTIPLES_OF_BRUSH_SIZE_PER_SECOND
+                        )
+                        .setSourceValueRangeStart(0f).setSourceValueRangeEnd(50f)
+                        .setSourceOutOfRangeBehavior(
+                            BrushBehavior.OutOfRange.OUT_OF_RANGE_CLAMP
+                        )
+                ).build()
+                val t = BrushBehavior.Node.newBuilder().setTargetNode(
+                    BrushBehavior.TargetNode.newBuilder()
+                        .setTarget(BrushBehavior.Target.TARGET_SIZE_MULTIPLIER)
+                        .setTargetModifierRangeStart(0.2f).setTargetModifierRangeEnd(2.0f)
+                ).build()
+                onAddBehavior(listOf(s, t))
+            }) { Text(stringResource(R.string.brush_designer_speed_size)) }
+        }
+
+        Button(modifier = Modifier.fillMaxWidth(), onClick = {
+            val s = BrushBehavior.Node.newBuilder().setSourceNode(
+                BrushBehavior.SourceNode.newBuilder()
+                    .setSource(
+                        BrushBehavior.Source
+                            .SOURCE_SPEED_IN_MULTIPLES_OF_BRUSH_SIZE_PER_SECOND
+                    )
+                    .setSourceValueRangeStart(5f).setSourceValueRangeEnd(40f)
+                    .setSourceOutOfRangeBehavior(
+                        BrushBehavior.OutOfRange.OUT_OF_RANGE_CLAMP
+                    )
+            ).build()
+            val t = BrushBehavior.Node.newBuilder().setTargetNode(
+                BrushBehavior.TargetNode.newBuilder()
+                    .setTarget(BrushBehavior.Target.TARGET_OPACITY_MULTIPLIER)
+                    .setTargetModifierRangeStart(1.0f).setTargetModifierRangeEnd(0.1f)
+            ).build()
+            onAddBehavior(listOf(s, t))
+        }) { Text(stringResource(R.string.brush_designer_speed_opacity)) }
+    }
+}
+
+@Composable
+private fun AdvancedDynamicsSection(
+    onAddBehavior: (List<BrushBehavior.Node>) -> Unit
+) {
+    Text(
+        stringResource(R.string.brush_designer_advanced_dynamics),
+        style = MaterialTheme.typography.labelLarge
+    )
+
+    Column(verticalArrangement = Arrangement.spacedBy(8.dp)) {
+        FilledTonalButton(
+            modifier = Modifier.fillMaxWidth(),
+            onClick = { onAddBehavior(PrefabBehaviors.pressureToSize()) }
+        ) {
+            Icon(
+                painterResource(R.drawable.brush_24px),
+                null,
+                Modifier.size(18.dp)
+            )
+            Spacer(Modifier.width(8.dp))
+            Text(stringResource(R.string.brush_designer_smooth_pressure_size))
+        }
+
+        FilledTonalButton(
+            modifier = Modifier.fillMaxWidth(),
+            onClick = { onAddBehavior(PrefabBehaviors.slantJitter()) }
+        ) {
+            Icon(
+                painterResource(R.drawable.texture_24px),
+                null,
+                Modifier.size(18.dp)
+            )
+            Spacer(Modifier.width(8.dp))
+            Text(stringResource(R.string.brush_designer_pencil_jitter))
+        }
+
+        FilledTonalButton(
+            modifier = Modifier.fillMaxWidth(),
+            onClick = { onAddBehavior(PrefabBehaviors.speedToOpacity()) }
+        ) {
+            Icon(
+                painterResource(R.drawable.opacity_24px),
+                null,
+                Modifier.size(18.dp)
+            )
+            Spacer(Modifier.width(8.dp))
+            Text(stringResource(R.string.brush_designer_smooth_speed_opacity))
+        }
+    }
+}