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/*
* Copyright 2015 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; version 3.
*
* This program 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
import QtQuick 2.0
import Lomiri.Components 1.3
Item {
id: root
width: 500
height: width * (15.0 / 16.0)
focus: true
// Zoom properties.
property variant translation: Qt.point(0.0, 0.0)
property real scaleBase: 1.1
property real scaleExponent: 0.0
property real minScaleExponent: 0.0
property real maxScaleExponent: 48.317715856 // Logarithm of 100 to base 1.1 (scaleBase).
property real scaleFactor: 1.0
property real scale: 1.0
// Overlay text properties.
property string textOverlayString:
"Zoom (scroll): x " + root.scaleFactor.toFixed(1) + "\n" +
"Width (a): " + shape.width.toFixed(2) + "\n" +
"Height (z): " + shape.height.toFixed(2)
// Main scene.
Item {
id: scene
anchors.fill: parent
Rectangle {
id: background
anchors.fill: parent
color: "white"
}
ProportionalShape {
id: shape
anchors.centerIn: parent
width: 300
source: Image { source: "music-app.png" }
}
}
// Zoom support.
ShaderEffectSource {
id: shaderEffectSource
anchors.fill: scene
sourceItem: scene
hideSource: true
visible: false
smooth: false
}
ShaderEffect {
anchors.fill: scene
property variant tex: shaderEffectSource
property variant translation: root.translation
property real scaleFactor: root.scale
vertexShader: "
uniform mat4 qt_Matrix;
uniform float scaleFactor;
uniform vec2 translation;
attribute vec4 qt_Vertex;
attribute vec2 qt_MultiTexCoord0;
varying vec2 texCoord;
void main() {
texCoord = vec2(scaleFactor) * qt_MultiTexCoord0 + translation;
gl_Position = qt_Matrix * qt_Vertex;
}"
fragmentShader: "
uniform sampler2D tex;
uniform float qt_Opacity;
varying vec2 texCoord;
void main() {
gl_FragColor = texture2D(tex, texCoord) * qt_Opacity;
}"
}
// Text overlay.
Text {
id: textOverlay
width:200
anchors.top: parent.top
anchors.topMargin: 10
anchors.left: parent.left
anchors.leftMargin: 10
font.family: "Noto Mono"
font.pixelSize: 14
font.weight: Font.Bold
color: "black"
text: textOverlayString
}
// Mouse handling.
MouseArea {
id: mouseArea
anchors.fill: parent
acceptedButtons: Qt.LeftButton
hoverEnabled: true
property real lastX: 0.0
property real lastY: 0.0
onPressed: {
if (pressedButtons & Qt.LeftButton) {
lastX = mouseX;
lastY = mouseY;
}
}
onPositionChanged: {
if (pressedButtons & Qt.LeftButton) {
var tx = root.translation.x;
var ty = root.translation.y;
var sx = root.scale / root.width;
var sy = root.scale / root.height;
var x = mouseX - lastX;
var y = mouseY - lastY;
root.translation = Qt.point(Math.max(0.0, Math.min(1.0 - root.scale, tx - sx * x)),
Math.max(0.0, Math.min(1.0 - root.scale, ty - sy * y)));
lastX = mouseX;
lastY = mouseY;
}
}
onWheel: {
root.scaleExponent = Math.max(minScaleExponent, Math.min(maxScaleExponent,
root.scaleExponent + (wheel.angleDelta.y < 0.0 ? -1.0 : 1.0)));
root.scaleFactor = Math.pow(root.scaleBase, root.scaleExponent);
var oldScale = root.scale;
root.scale = 1.0 / root.scaleFactor;
var s = oldScale - root.scale;
var tx = root.translation.x;
var ty = root.translation.y;
var x = mouseX / root.width;
var y = mouseY / root.height;
root.translation = Qt.point(Math.max(0.0, Math.min(1.0 - root.scale, tx + s * x)),
Math.max(0.0, Math.min(1.0 - root.scale, ty + s * y)));
}
}
// Keyboard handling.
Keys.onPressed: {
var shift = Qt.ShiftModifier;
if (event.key == Qt.Key_A) {
shape.width = Math.max(0.0, shape.width + ((event.modifiers & shift) ? 2.0 : -2.0));
} else if (event.key == Qt.Key_Z) {
shape.height = Math.max(0.0, shape.height + ((event.modifiers & shift) ? 2.0 : -2.0));
}
}
}
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